The average monthly income of P and Q is Rs. 5050. The average monthly income of Q and R is Rs. 6250 and the average monthly income of P and R is Rs. 5200. The monthly income of P is:
Aptitude
Average
Difficulty: Medium
Choose an option
Answer
Correct Answer: Rs. 4,000
Explanation
Given average pairs
- Avg(P, Q) = 5050 ⇒ P + Q = 10,100
- Avg(Q, R) = 6250 ⇒ Q + R = 12,500
- Avg(P, R) = 5200 ⇒ P + R = 10,400
Step 1: Add (P + Q) and (P + R)(P + Q) + (P + R) = 10,100 + 10,400 = 20,500Left side = 2P + (Q + R)
Step 2: Substitute (Q + R)Q + R = 12,500So 2P + 12,500 = 20,500 ⇒ 2P = 8,000 ⇒ P = Rs. 4,000
Check
- P + Q = 10,100 ⇒ Q = 6,100; P + R = 10,400 ⇒ R = 6,400; then Avg(Q, R) = (6100 + 6400)/2 = 6250 ✓
Final AnswerMonthly income of P = Rs. 4,000.