The average of 4 numbers is 21. If the average of first two numbers is 18, what is the average of the last two numbers? MCQ with Answer and Explanation

The average of 4 numbers is 21. If the average of first two numbers is 18, what is the average of the last two numbers?

A. 24

B. 22

C. 21.5

D. 23

Answer: Option A

Sum of all =4×21=84. Sum of first two =2×18=36. Sum of last two =84-36=48. Average of last two =48/2=24.

This question belongs to: Maths Average

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Question #1 Report Error

Average of 8 numbers 2700. If average of 5 is 2695, average of remaining 3?

A. 2710

B. 2707

C. 2705

D. 2708.33

Correct Answer: Option D

Explanation:
Sum8=21600. Sum5=13475. Remaining=8125. Average≈2708.33.

This question belongs to: Maths Average

Question #2 Report Error

The average of 8 numbers is 27. If average of 5 is 25, average of remaining 3?

A. 28

B. 30

C. 29

D. 31

Correct Answer: Option B

Explanation:
Sum8=216. Sum5=125. Remaining=91. Average≈30.33 approx 30.

This question belongs to: Maths Average

Question #3 Report Error

The average weight of 8 persons increases by 2.5 kg when one person weighing 65 kg is replaced by a new person. What is the weight of the new person?

A. 80

B. 75

C. 85

D. 90

Correct Answer: Option C

Explanation:
Increase in total weight = 8 × 2.5 = 20 kg. New person weight = 65 + 20 = 85 kg.

This question belongs to: Maths Average