The average weight of P, Q, and R is 47 kg. If the average weight of Q and R is 50 kg and that of R and P is 49 kg, then the average weight (in kg) of P and Q is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 42.
P + Q + R = 47 × 3 = 141 kg
Q + R = 50 × 2 = 100 kg
R + P = 49 × 2 = 98 kg
P's weight = (P + Q + R) - (Q + R) = 141 - 100 = 41 kg
Q's weight = (P + Q + R) - (R + P) = 141 - 98 = 43 kg
R's weight = (Q + R) - Q = 100 - 43 = 57 kg
Average of P and Q = (41 + 43)/2 = 84/2 = 42 kg