Olympiad Test: Integers -2 - Free MCQ with solutions Class 7 Mathematics

72 ÷ x = – 4

Additive inverse of 7 = –7
Multiplicative inverse of

[16 – {5 + (2 – 7)}] – [12 – {7 – (3 – 4)}]
= [16 – {5 – 5}] – [12 – {7 + 1}]
= [16 – 0] – [12 – 8] = 16 – 4 = 12

 [16 ÷ {11 – (2 + 5)}]
= [16 ÷ {11 – 7}] = [ 16 ÷ 4] = 4

25+16 ÷ 4×3 –5+7 of (–3)
= 25 + 16 ÷ 4×3 –5 + (–21)
= 25 + 4×3 –5 –21
= 25 + 12–26
= 37 – 26 = 11

Given expression:

((1/3 + 2/5) of 2/3) - ((4/5 * 5/7) of 7/11) = ?

Step 1: Simplify the expressions within the parentheses:

• (1/3 + 2/5) = (5/15 + 6/15) = 11/15
• (4/5 * 5/7) = 4/7

Step 2: Substitute the simplified expressions back into the original equation:

((11/15) of 2/3) - ((4/7) of 7/11) = ?

Step 3: Calculate the "of" operations (which means multiplication):

• (11/15) of 2/3 = (11/15) * (2/3) = 22/45
• (4/7) of 7/11 = (4/7) * (7/11) = 4/11

Step 4: Substitute the calculated values back into the equation:

22/45 - 4/11 = ?

Step 5: Find a common denominator for the fractions:

• The least common multiple of 45 and 11 is 495.
• Convert the fractions to equivalent fractions with a denominator of 495:
  • 22/45 = (22 * 11) / (45 * 11) = 242/495
  • 4/11 = (4 * 45) / (11 * 45) = 180/495

Step 6: Subtract the fractions:

242/495 - 180/495 = (242 - 180) / 495 = 62/495

Therefore, the value of the expression is 62/495.

Profit on one white cement bag = Rs. 8

Loss on one grey cement bag = - Rs. 5 [Loss is considered to be negative]

Profit on 3,000 bags of white cement = 3,000 × Rs. 8 = Rs. 24,000

Loss on 5,000 bags of white cement = - 5,000 × Rs. 5 = - Rs. 25,000

Since the loss amount is greater than the profit amount,

Total loss = - Rs. 25,000 + Rs. 24,000 = - Rs. 1,000 

i.e. the total loss amount is Rs.1000.

Marks for 9 correct answers = 9 × 4 = 36
Marks for 6 incorrect answers = 6 × (–2) = –12
Mohan’s total score = 36 + (–12) = 36 –12 = 24

Given:
Profit per copy = Rs 1
Loss per pen = Rs 0.40 (40 paise = 0.40 Rs)
Total loss = Rs 5
Copies sold = 45
We need to find number of pens sold.
Let No. of pens sold = x

Step 1: Profit from selling copies
Profit from 45 copies = 45 × 1 = 45 Rs

Step 2: Total loss
Loss on pens = 0.40 × x = 0.40x Rs
Net loss = Total loss – Profit from copies
Since he incurred an overall loss of Rs 5, we can write:
Loss on pens − Profit on copies = 5
0.40x − 45 = 5

Step 3: Solve for x
0.40x = 5 + 45
0.40x = 50
x = 50/0.40
x = 125

Hence, No. of pens sold = 125
So, Correct Option: C

The temperature at 12 noon = 10°C (given)

The temperature decreases by 2°C in 1 hour (given)

Thus, the temperature decreases by 1°C in 1/2 hour

Temperature 10°C above zero - Temperature 8°C below zero = 10 - (- 8) = 10 + 8 = 18°C

The temperature decreases by 18°C in 1/2 × 18 = 9 hours

Thus, from 10°C above zero to 8°C below zero it takes 9 hours

Total time = 12 noon + 9 hours

= 21 hours = 9 pm

Thus, at 9 pm temperature would be 8°C below zero.