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The sum of 3 consecutive even number is 40 more than the average of these numbers. Which of the following is the 2 largest number ?
X+x+2+x+4 = 40+(x+x+2+x+4)/3
3x+6 = 40+ (3x+6)/3
(9x+18 – 3x6)/3= 40
6x + 12 = 120
X = 108/6 = 18
18+2 = 20
The sum of 3 consecutive number is 1251, Find the largest even number ?
X+x+1+x+2 = 1251
3x+3 = 1251
X = 1248/3 = 416
X+2 = 416+2 = 418
What is the least number that can be added to 7218 make it a perfect square ?
85*85 = 7225
If a = 2 and b = 5 then find the value of a^{3} + b^{3}– a^{2} + b^{2} + 2a – 3b
a^{3} + b^{3}– a^{2} + b^{2} + 2a – 3b
(2)^{3} + (5)^{3} – (2)^{2} + (5)^{2} + 2(2) – 3(5) = 8 1254+254+15 = 101
X+(1/X) = 2 ;
(X^2+ 1)/ X = 2 ;
X^2+1 = 2X ;
X^2  2X + 1= 0 ;
By factorisation method ,
X = 1 ;
Now substitute X= 1 in X +(1/X) ;
we get , 1  1/1 = 0 ;
Therefore , X = 0 ;
The average of 7 consecutive number is n, if the next 2 number also included then the new average will be increased by ?
Avg of 7 no= (7+1)/2 = 8/2 = 4
Avg of 9 no = (9+1)/2 = 5
5 4 = 1
Hence increased by 1
When a positive number n is divided by 7 leaves the remainder 2, when 3n is divided by the same number, then the remainder is
N = 7+2 =9
3n = 27
27/7 = 6
2*3*5*7*11*13*17 = 510510
25% of a number is 2 time 65% of another number.Find the ratio of the second no to the first number ?
(a*25)/100 = b(2*65)/100
a*25 = b*130
a/b = 130/25 = 26/5
b:a = 5:26
Square number can never end in 2,7
When a number is subtracted from the number 8,12 and 20, the remainders are in continued proportion, Find the number ?
8x / 12 –x = 12x /20 –x
(8x)(20x) = (12 – x)(12 –x)
160 – 8x – 20x + x^{2} = 144 – 12x – 12x + x^{2}
4x = 16
x = 4
Sum of the three consecutive number is 1956. What is 23% of the highest number ?
X+x+1+x+2 = 1956
3x = 1956 – 3 = 1953
X = 1953/3 = 651
X+3 = 653
23% of largest num = 23*653/100 = 150.19
If the numerator of a fraction is increased by 100% and the denominator is increased by 200%. The resultant fraction is 1 (1/15), What was the original fraction ?
1(1/15) = 16/15
X+x/y+2y = 16/15
2x/3y = 16/15
x/y = (16*3) / (15*2) = 8/5 = 1(3/5)
(9+3+4+7) – (2+4+5+1) = 11
The sum of square of 2 number is 1972 and the difference of their square is 620. Find the number ?
X^{2} + y^{2} = 1972
X^{2} – y^{2} = 620
Solve this
2x^{2} = 2592
x = 1296
x = 36
y^{2} = 1972 – 1296
y^{2} = 676
y = 26
Product of one fourth of the number and 120% of another number is what % of the product of the original number ?
x/4 = one fourth of the no
120y/100 = another no = 6y/5
% = [(x/4 * 6y/5)*100] / xy
= 600/20 = 30%
Find the 5 digit number, 5^{th} digit is one fourth of the 3^{rd} digit and one half of the 4^{th} digit. 3^{rd} digit is one half of the 1^{st} digit. 2^{nd} digit is 5 more than the 5^{th} digit.
5^{th} digit – 1
Second – 1+5 = 6
Third = 4
Four = 2
First = 4*2 = 8
What is the no of zeroes at the end of the product of the no from1 to 100 ?
100/5 + 100/25 = 20+4 = 24
7y+y = 4
8y = 8 Y = 1
If three numbers are added in pairs, the sums equal to 11,16 and 23.Find the three numbers
X+y = 11
Y+z = 16
Z+x = 23
X+y+z = 25
X = 25 – 16 = 9
y = 25 – 23 = 2
z = 25 – 11 = 14
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