The average weight of A, B and C is 65 kg. If the average weight of A and B is 62 kg and that of B and C is 66 kg, then the weight (in kg) of B is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 61.
We know that,
Average = Sum of observations/Number of observations
Now,
The sum of the weight of A, B and C = 65 × 3 = 195 ---- (1)
The sum of the weight of A and B = 62 × 2 = 124 ---- (2)
Equating (1) - (2), we get
⇒ A + B + C - A - B = 195 - 124
⇒ C = 71
The sum of the weight of B and C = 66 × 2 = 132
⇒ B + C = 132
⇒ B + 71 = 132
⇒ B = 132 - 71 = 61
Hence, the weight of B is 61 kg