Think of a 4-letter word as: 1st – 2nd – 3rd – 4th.
Rule: swap the 1st and 4th letters; keep the 2nd and 3rd the same.
TEAM → (swap T and M) → MEAT
HEAR → (swap H and R) → REAH ✅ (option b)
HEAR → (swap H and R) → REAH ✅ (option b)
All Exams > Class 8 > Mathematical Olympiad Class 8 > All Questions
All questions of Coding-Decoding for Class 8 Exam
If ‘sky’ is ‘star ’, ‘star ’ is ‘cloud’, ‘cloud’ is earth, ‘earth’ is ‘tree’ and ‘tree’ is ‘book’, then where do the birds fly?- a)Sky
- b)Cloud
- c)Star
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
If ‘sky’ is ‘star ’, ‘star ’ is ‘cloud’, ‘cloud’ is earth, ‘earth’ is ‘tree’ and ‘tree’ is ‘book’, then where do the birds fly?
a)
Sky
b)
Cloud
c)
Star
d)
None of these
 | Ananya Das answered |
Birds fly in the ‘sky’ and as given, ‘sky’ is ‘star’. So, birds fly in the ‘star’.
In a certain code, INACTIVE is written as VITCANIE. How is COMPUTER written in the same code?- a)UTEPMOCR
- b)MOCPETUR
- c)ETUPMOCR
- d)PMOCRETU
Correct answer is option 'C'. Can you explain this answer?
In a certain code, INACTIVE is written as VITCANIE. How is COMPUTER written in the same code?
a)
UTEPMOCR
b)
MOCPETUR
c)
ETUPMOCR
d)
PMOCRETU
 | Rajveer Verma answered |
All the letters of the word, except the last letter, are written in a reverse order to obtain the code.
If ‘dust’ is called ‘air ’, ‘air ’ is called ‘fire’, ‘fire’ is called ‘water’, ‘water’ is called ‘colour’, ‘colour’ is called ‘rain’ and ‘rain’ is called ‘dust’, then where do fish live?- a)Dust
- b)Water
- c)Colour
- d)Fire
Correct answer is option 'C'. Can you explain this answer?
If ‘dust’ is called ‘air ’, ‘air ’ is called ‘fire’, ‘fire’ is called ‘water’, ‘water’ is called ‘colour’, ‘colour’ is called ‘rain’ and ‘rain’ is called ‘dust’, then where do fish live?
a)
Dust
b)
Water
c)
Colour
d)
Fire
 | Sanskriti Tiwari answered |
Fishes l ive in ‘water’ and as given, ‘water’ is called ‘colour’. So, fishes live in ‘colour’.
In a certain code, the words COME AT ONCE, were written as XLNVZGLMXV. In the same code, which of the following would code OK?- a)LP
- b)KM
- c)LM
- d)KL
Correct answer is option 'A'. Can you explain this answer?
In a certain code, the words COME AT ONCE, were written as XLNVZGLMXV. In the same code, which of the following would code OK?
a)
LP
b)
KM
c)
LM
d)
KL
 | Maheshwar Kumar answered |
Each letter in the word is replaced by the letter which occupies the same position from the other end of the alphabet, to obtain the code.
If GO = 32, SHE = 49, then SOME will be equal to- a)64
- b)62
- c)56
- d)58
Correct answer is option 'C'. Can you explain this answer?
If GO = 32, SHE = 49, then SOME will be equal to
a)
64
b)
62
c)
56
d)
58
 | Rajat Menon answered |
In the given code, Z = 1, Y = 2, X = 3, ……. C = 24, B = 25, Z = 26.
So, GO = 20 + 12 = 32 and SHE = 8 + 19 + 22 = 49.
Similarly, SOME = S + O + M + E = 8 + 12 + 14 + 22 = 56.
So, GO = 20 + 12 = 32 and SHE = 8 + 19 + 22 = 49.
Similarly, SOME = S + O + M + E = 8 + 12 + 14 + 22 = 56.
In a certain code, BRAIN is written as * % ÷ # × and TIER is written as $ # + %. How is RENT written in that code?- a)% × # $
- b)% # × $
- c)+ × % $
- d)% + × $
Correct answer is option 'D'. Can you explain this answer?
In a certain code, BRAIN is written as * % ÷ # × and TIER is written as $ # + %. How is RENT written in that code?
a)
% × # $
b)
% # × $
c)
+ × % $
d)
% + × $
 | Shilpa Kulkarni answered |
Letter : B R A I N T E
Code : ∗ % ÷ # × $ +
The code for RENT is % + × $
Code : ∗ % ÷ # × $ +
The code for RENT is % + × $
If ENGLAND is written as 1234526 and FRANCE is written as 785291, how is GREECE coded?- a)835545
- b)381191
- c)832252
- d)381171
Correct answer is option 'B'. Can you explain this answer?
If ENGLAND is written as 1234526 and FRANCE is written as 785291, how is GREECE coded?
a)
835545
b)
381191
c)
832252
d)
381171
 | Abhijeet Choudhary answered |
Letter: E N G L A D F R C
Code: 1 2 3 4 5 6 7 8 9
The code for GREECE is 381191.
Code: 1 2 3 4 5 6 7 8 9
The code for GREECE is 381191.
In a certain code, VISHWANATHAN is written as NAAWTHHSANIV. How is KARUMAKARANA written in that code?- a)KAAMRAURMAAK
- b)NKKRAMKRAUK
- c)RURNKAAUNAK
- d)AKNUARRAANKA
Correct answer is option 'A'. Can you explain this answer?
In a certain code, VISHWANATHAN is written as NAAWTHHSANIV. How is KARUMAKARANA written in that code?
a)
KAAMRAURMAAK
b)
NKKRAMKRAUK
c)
RURNKAAUNAK
d)
AKNUARRAANKA
 | Subham Verma answered |
Divide the given word into six sets of two letters each and label these sets from 1 to 6.
Then the code contains these sets in the order 4, 3, 5, 2, 6, 1 with the letters of sets 3, 2, 1 written in a reverse order. Thus, we have:
Then the code contains these sets in the order 4, 3, 5, 2, 6, 1 with the letters of sets 3, 2, 1 written in a reverse order. Thus, we have:
If NOIDA is written as 39658, how will INDIA be written?- a)36568
- b)65368
- c)63568
- d)63569
Correct answer is option 'C'. Can you explain this answer?
If NOIDA is written as 39658, how will INDIA be written?
a)
36568
b)
65368
c)
63568
d)
63569
 | Amrita Roy answered |
Letter : N O I D A
Code : 3 9 6 5 8
The code for INDIA is 63568.
Code : 3 9 6 5 8
The code for INDIA is 63568.
In a certain code, DEAF is written as 3587 and FILE is written as 7465. How is IDEAL written in that code?- a)63548
- b)43568
- c)43586
- d)48536
Correct answer is option 'C'. Can you explain this answer?
In a certain code, DEAF is written as 3587 and FILE is written as 7465. How is IDEAL written in that code?
a)
63548
b)
43568
c)
43586
d)
48536
| | Shivam Chakraborty answered |
Understanding the Code
To decode how the words are transformed into numbers, we analyze the examples provided:
1. Analyzing DEAF = 3587
- D = 3
- E = 5
- A = 8
- F = 7
2. Analyzing FILE = 7465
- F = 7
- I = 4
- L = 6
- E = 5
Identifying Patterns
From the above analyses, we can observe the following mappings for the letters:
- D = 3
- E = 5
- A = 8
- F = 7
- I = 4
- L = 6
Mapping IDEAL
Now, let's apply these mappings to the word IDEAL:
- I = 4
- D = 3
- E = 5
- A = 8
- L = 6
Combining the Numbers
When we put these numbers together according to the letters in "IDEAL", we get:
- I (4), D (3), E (5), A (8), L (6)
This results in the sequence: 43586.
Conclusion
Thus, the code for the word IDEAL is 43586, which corresponds to option 'C'.
To decode how the words are transformed into numbers, we analyze the examples provided:
1. Analyzing DEAF = 3587
- D = 3
- E = 5
- A = 8
- F = 7
2. Analyzing FILE = 7465
- F = 7
- I = 4
- L = 6
- E = 5
Identifying Patterns
From the above analyses, we can observe the following mappings for the letters:
- D = 3
- E = 5
- A = 8
- F = 7
- I = 4
- L = 6
Mapping IDEAL
Now, let's apply these mappings to the word IDEAL:
- I = 4
- D = 3
- E = 5
- A = 8
- L = 6
Combining the Numbers
When we put these numbers together according to the letters in "IDEAL", we get:
- I (4), D (3), E (5), A (8), L (6)
This results in the sequence: 43586.
Conclusion
Thus, the code for the word IDEAL is 43586, which corresponds to option 'C'.
In a certain code, RAIL is written as KCTN and SPEAK is written as CGRUM. How will AVOID be written in that code?- a)FKQXC
- b)KQVCB
- c)KQXCF
- d)KRXCF
Correct answer is option 'C'. Can you explain this answer?
In a certain code, RAIL is written as KCTN and SPEAK is written as CGRUM. How will AVOID be written in that code?
a)
FKQXC
b)
KQVCB
c)
KQXCF
d)
KRXCF
| | Subham Verma answered |
All the letters of the word, except the last letter, are written in the reverse order and in the group of letters so obtained each letter is moved into steps forward to get the code.
AVOID → IOVAD → KQXCF.
AVOID → IOVAD → KQXCF.
If CONTRIBUTE is written as ETBUIRNTOC, then which letter will be in the sixth place when counted from the left it POPULARISE is written in the same way?- a)L
- b)A
- c)R
- d)I
Correct answer is option 'A'. Can you explain this answer?
If CONTRIBUTE is written as ETBUIRNTOC, then which letter will be in the sixth place when counted from the left it POPULARISE is written in the same way?
a)
L
b)
A
c)
R
d)
I
| | Rajveer Verma answered |
Clearly, the sixth letter from the left in the code is L.
In a certain code, EAT is written as 318 and CHAIR is written as 24156. What will TEACHER be written as?- a)8313426
- b)8321436
- c)8312346
- d)8312436
Correct answer is option 'D'. Can you explain this answer?
In a certain code, EAT is written as 318 and CHAIR is written as 24156. What will TEACHER be written as?
a)
8313426
b)
8321436
c)
8312346
d)
8312436
 | Anshu Nambiar answered |
Letter: E A T C H I R
Code: 3 1 8 2 4 5 6
The code for TEACHER is 8312436.
Code: 3 1 8 2 4 5 6
The code for TEACHER is 8312436.
If REQUEST is written as S2R52TU, then how will ACID be written?- a)ID3E
- b)IC94
- c)B3J4
- d)1394
Correct answer is option 'A'. Can you explain this answer?
If REQUEST is written as S2R52TU, then how will ACID be written?
a)
ID3E
b)
IC94
c)
B3J4
d)
1394
 | Shilpa Dasgupta answered |
Vowels A, E, I, O, U are coded as 1, 2, 3, 4, 5 respectively. Each of the consonants in the word is moved one step forward to give the corresponding letter of the code so, the code for ACID becomes ID3E.
In a certain code language, ‘GRASP’ is ‘BMVNK' what will be the code for the word ‘CRANE’?- a)FUDQH
- b)XMVIZ
- c)GVERI
- d)HWFSJ
Correct answer is option 'B'. Can you explain this answer?
In a certain code language, ‘GRASP’ is ‘BMVNK' what will be the code for the word ‘CRANE’?
a)
FUDQH
b)
XMVIZ
c)
GVERI
d)
HWFSJ
 | Swara Chakraborty answered |
Explanation:
- Given: GRASP is coded as BMVMK
- The letters in the word GRASP are shifted by a certain number of positions to get the coded word BMVMK.
- Let's find the shift by comparing the positions of letters in the original word and the coded word:
- G -> B (shift of 4 positions)
- R -> M (shift of 6 positions)
- A -> V (shift of 4 positions)
- S -> M (shift of 6 positions)
- P -> K (shift of 6 positions)
- So, the letters in the coded word are 4, 6, 4, 6, and 6 positions ahead of the corresponding letters in the original word.
- Applying the same shift to the word CRANE:
- C -> H (shift of 5 positions)
- R -> W (shift of 6 positions)
- A -> F (shift of 5 positions)
- N -> S (shift of 5 positions)
- E -> J (shift of 5 positions)
- Therefore, the word CRANE would be coded as HWFSJ.
Correct Answer: b) HWFSJ
In a certain code language 'A' is coded as '5', 'B' is coded as '6', 'C' is coded as '7' and so on, then find the code of 'DDCE'.- a)7988
- b)9788
- c)8978
- d)8879
Correct answer is option 'B'. Can you explain this answer?
a)
7988
b)
9788
c)
8978
d)
8879
 | Shiksha Academy answered |
Following the pattern where each letter is represented by its position in the alphabet, 'D' corresponds to '4', 'E' corresponds to '5', so 'DDCE' translates to '4455' which is '9788'.
If ‘blue’ means ‘green’, ‘green’ means ‘white’, ‘white’ means ‘yellow’ means ‘black’, ‘black’ means ‘red’ and ‘red’ means ‘brown’, then what is the colour of milk?- a)Green
- b)Yellow
- c)Blue
- d)Black
Correct answer is option 'A'. Can you explain this answer?
If ‘blue’ means ‘green’, ‘green’ means ‘white’, ‘white’ means ‘yellow’ means ‘black’, ‘black’ means ‘red’ and ‘red’ means ‘brown’, then what is the colour of milk?
a)
Green
b)
Yellow
c)
Blue
d)
Black
| | Anshu Nambiar answered |
The colour of milk is ‘white’. But, as given ‘green’ means ‘white’. So, the colour of milk is green.
If TRUTH is coded as SUQSTVSUGI, then the code for FALSE will be- a)FGZBKNRTDF
- b)EGZBKMRDE
- c)EGZKMRTDF
- d)EGZBKMRTDF
Correct answer is option 'D'. Can you explain this answer?
If TRUTH is coded as SUQSTVSUGI, then the code for FALSE will be
a)
FGZBKNRTDF
b)
EGZBKMRDE
c)
EGZKMRTDF
d)
EGZBKMRTDF
| | Rajveer Verma answered |
Each letter of the word ‘TRUTH’ is replaced by a set of two letters – one preceding it and the other following it – in the code. Thus, T is replaced by SU, R is replaced by QS and so on.
If ZIP = 198 and ZAP = 246, then how will you code VIP?- a)888
- b)990
- c)222
- d)174
Correct answer is option 'C'. Can you explain this answer?
If ZIP = 198 and ZAP = 246, then how will you code VIP?
a)
888
b)
990
c)
222
d)
174
| | Sanskriti Tiwari answered |
Taking Z = 2, Y = 3, …., N = 14, ……, B = 26,
A = 27
ZIP
= (Z + I + P) × 6 = (2 + 19 + 12) × 6 = 33 × 6
= 198
VIP
= (V + I + P) × 6 = (6 + 19 + 12) × 6 = 37 × 6
= 222
A = 27
ZIP
= (Z + I + P) × 6 = (2 + 19 + 12) × 6 = 33 × 6
= 198
VIP
= (V + I + P) × 6 = (6 + 19 + 12) × 6 = 37 × 6
= 222
In a certain code, FIRE is written as QHOE and MOVE as ZMWE. Following the same rule of coding what should be the code for the word OVER?- a)MWZO
- b)MWED
- c)MWEO
- d)MWOE
Correct answer is option 'C'. Can you explain this answer?
In a certain code, FIRE is written as QHOE and MOVE as ZMWE. Following the same rule of coding what should be the code for the word OVER?
a)
MWZO
b)
MWED
c)
MWEO
d)
MWOE
| | Shilpa Kulkarni answered |
Letter: F I R E M O V
Code: Q H O E Z M W
The code for OVER is MWEO.
Code: Q H O E Z M W
The code for OVER is MWEO.
If NARGRUED is the code for GRANDEUR, which word is coded as SERPEVRE?- a)PRESEVER
- b)PERSERVE
- c)PERSEVER
- d)PRESERVE
Correct answer is option 'D'. Can you explain this answer?
If NARGRUED is the code for GRANDEUR, which word is coded as SERPEVRE?
a)
PRESEVER
b)
PERSERVE
c)
PERSEVER
d)
PRESERVE
| | Maheshwar Kumar answered |
The code has been obtained by writing the first four and the last four letters of the word in the reverse order. Thus, we have.
SERPEVRE → SERP/EVRE → PRES/ERVE → PRESERVE.
SERPEVRE → SERP/EVRE → PRES/ERVE → PRESERVE.
If DELHI is coded as 73541 and CALCUTTA as 82589662, how can CALICUT be coded?- a)8251896
- b)8543691
- c)5978213
- d)5279431
Correct answer is option 'A'. Can you explain this answer?
If DELHI is coded as 73541 and CALCUTTA as 82589662, how can CALICUT be coded?
a)
8251896
b)
8543691
c)
5978213
d)
5279431
| | Anshu Nambiar answered |
Letter: D E L H I C A U T
Code: 7 3 5 4 1 8 2 9 6
The code for CALICUT is 8251896.
Code: 7 3 5 4 1 8 2 9 6
The code for CALICUT is 8251896.
In a certain code, DESK is written as #. 52, RIDE is written as % 7# . how is RISK written in that code?- a)% 7 $ #
- b)% 752
- c)% 7 # 2
- d)% 725
Correct answer is option 'B'. Can you explain this answer?
In a certain code, DESK is written as #. 52, RIDE is written as % 7# . how is RISK written in that code?
a)
% 7 $ #
b)
% 752
c)
% 7 # 2
d)
% 725
| | Shilpa Kulkarni answered |
Letter: D E S K R I
Code: # 5 2 % 7
The code for RISK is % 752.
Code: # 5 2 % 7
The code for RISK is % 752.
If WORK is coded as 4 – 12 – 9 – 16, then how will you code WOMAN?- a)23 – 12 – 26 – 14 – 13
- b)4 – 12 – 14 – 26 – 13
- c)4 – 26 – 14 – 13 – 12
- d)23 – 15 – 13 – 1 – 14
Correct answer is option 'B'. Can you explain this answer?
If WORK is coded as 4 – 12 – 9 – 16, then how will you code WOMAN?
a)
23 – 12 – 26 – 14 – 13
b)
4 – 12 – 14 – 26 – 13
c)
4 – 26 – 14 – 13 – 12
d)
23 – 15 – 13 – 1 – 14
| | Abhijeet Choudhary answered |
Each letter is coded by the numeral obtained by subtracting from 27 then numeral denoting the position of the letter in the English alphabet. W, O, M, A, N are 23rd, 15th, 13th, 1st and 14th letters. So their codes are (27 – 23), (27 – 15), (27 – 13), (27 – 1), (27 – 14)
i.e. 4, 12, 14, 26, 13 respectively.
i.e. 4, 12, 14, 26, 13 respectively.
If ‘eraser ’ is called ‘box’, ‘box’ is called ‘pencil’, ‘pencil’ is called ‘sharpener’ and ‘sharpener’ is called ‘bag’, what will a child write with?- a)Box
- b)Sharpener
- c)Bag
- d)Pencil
Correct answer is option 'B'. Can you explain this answer?
If ‘eraser ’ is called ‘box’, ‘box’ is called ‘pencil’, ‘pencil’ is called ‘sharpener’ and ‘sharpener’ is called ‘bag’, what will a child write with?
a)
Box
b)
Sharpener
c)
Bag
d)
Pencil
| | Rajat Menon answered |
A child will write with a ‘pencil’ and ‘pencil’ is called sharpener. So, a child will write with a ‘sharpener’.
If MASTER is coded as 
, then POWDER will be coded as.- a)
- b)
- c)
- d)
Correct answer is option 'B'. Can you explain this answer?
If MASTER is coded as , then POWDER will be coded as.
, then POWDER will be coded as.a)
b)
c)
d)
 | Athira Desai answered |
Let A = 1, B = 2, C = 3, ……, Z = 26. Now, M = 13 = 4 (Remainder obtained after dividing by 9).
S = 19 = 1 (Remainder obtained after dividing by 9 twice)
T = 20 = 2 (Remainder obtained after dividing by 9 twice)
(Remainder obtained after dividing by 9)
S = 19 = 1 (Remainder obtained after dividing by 9 twice)
T = 20 = 2 (Remainder obtained after dividing by 9 twice)
(Remainder obtained after dividing by 9)If ‘Oranges’ are ‘apples’, ‘bananas’ are ‘apricots’, ‘apples’ are ‘chillies’, ‘apricots’ are ‘oranges’ and chillies are ‘bananas’, then which of the following are green in colour?- a)Chillies
- b)Oranges
- c)Apples
- d)Bananas
Correct answer is option 'D'. Can you explain this answer?
If ‘Oranges’ are ‘apples’, ‘bananas’ are ‘apricots’, ‘apples’ are ‘chillies’, ‘apricots’ are ‘oranges’ and chillies are ‘bananas’, then which of the following are green in colour?
a)
Chillies
b)
Oranges
c)
Apples
d)
Bananas
| | Shilpa Dasgupta answered |
‘Chillies’ are green in colour and as given, ‘chillies’ are ‘bananas’. So, ‘bananas’ are green in colour.
If code of 'EF' is 'FG', then find the code of 'AB'.- a)DE
- b)BA
- c)CB
- d)BC
Correct answer is option 'D'. Can you explain this answer?
If code of 'EF' is 'FG', then find the code of 'AB'.
a)
DE
b)
BA
c)
CB
d)
BC
| | Shiksha Academy answered |
In the given pattern, each letter seems to be moving one step ahead. For instance, E becomes F and F becomes G. Following the same logic, A will become B and B will become C, resulting in the code 'BA'.
If 'Sugar' is called 'Book', 'Book' is called 'Salt', and 'Salt' is called 'Sweet', what do we read?- a)Sugar
- b)Sweet
- c)Book
- d)Salt
Correct answer is option 'A'. Can you explain this answer?
If 'Sugar' is called 'Book', 'Book' is called 'Salt', and 'Salt' is called 'Sweet', what do we read?
a)
Sugar
b)
Sweet
c)
Book
d)
Salt
 | Learning Enablers answered |
We are given:
- 'Sugar' is called 'Book'
- 'Book' is called 'Salt'
- 'Salt' is called 'Sweet'
To understand what we read, let's break it down:
- Normally, we read a book.
- According to the coding, 'Book' is called 'Salt'.
- 'Salt' is called 'Sweet'.
- Since the question is asking what we typically read, it would be Sugar, as the word 'Sugar' has been substituted as 'Book' in the code.
Thus, the correct answer is Sugar.
If DRIVER = 12, PEDESTRIAN = 20, ACCIDENT = 16, then CAR = ?- a)6
- b)8
- c)10
- d)3
Correct answer is option 'A'. Can you explain this answer?
If DRIVER = 12, PEDESTRIAN = 20, ACCIDENT = 16, then CAR = ?
a)
6
b)
8
c)
10
d)
3
| | Amrita Roy answered |
CAR = (Number of letters in CAR) × 2 = 3 × 2 = 6
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