The average weight of P, Q, and R is 57 kg. If the average weight of Q and R is 60 kg and that of R and P is 59 kg, then the weight (in kg) of R is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 67.
P + Q + R = 57 × 3 = 171 kg....(1)
Q + R = 60 × 2 = 120 kg....(2)
R + P = 59 × 2 = 118 kg....(3)
Now,
Add equations 2 and 3
⇒ Q + R + R + P = 120 + 118
⇒ P + Q + 2R = 238 kg
⇒ R = (P + Q + 2R) - (P + Q + R)
⇒ R = 238 - 171 = 67 Kg