The average monthly income of P and Q is Rs. 6000; that of Q and R is Rs. 5250; and that P and R is Rs. 5500. What is P’s monthly income?

Answer: Option C

Average monthly income of P and Q = Rs. 6000
Average monthly income of Q and R = Rs. 5250
Average monthly income of P and R = Rs. 5500
Total income of P + Q
= 2 × 6000
= Rs. 12000.....(i)
Total income of Q + R
= 2 × 5250
= Rs. 10500.....(ii)
Total income of R + P
= 2 × 5500
= Rs. 11000.....(iii)
On adding equation (i) (ii) and (iii), we have
2 (P + Q + R) = 12000 + 10500 + 11000
⇒ P + Q + R = $$\frac{33500}{2}$$
⇒ P + Q + R = Rs. 16750.....(iv)
By equation (iv) - (ii)
P's monthly income
= Rs. (16750 - 10500)
= Rs. 6250