Q. The average of three numbers p, q and r is k. p is as much more than the average as q is less than the average. What is the value of r?
(a) k
(b) k-1
(c) k+1
(d) k/2
Correct Answer : (a) k
UPSC Prelims 2025 CSAT
Explanation :
1. Given that the average of p, q and r is k, so
(p + q + r)/3 = k
⇒ p + q + r = 3k.
2. We are also told that “p is as much more than the average as q is less than the average,” i.e.
p – k = k – q
⇒ p + q = 2k.
3. Substitute p + q = 2k into p + q + r = 3k:
2k + r = 3k
⇒ r = 3k – 2k = k.
Answer: (a) k.
