The average weight of T, U and V is 42 kg. If the average weight of T and U is 40 kg and the average weight of U and V is 36 kg, then what is the weight of U?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 26 kg.
Let the weights of T, U, and V be represented as ( t), ( u), and ( v) respectively.
⇒t + u + v / 3 = 42 ⇒ t + u + v = 126......(1)
The average weight of T and U is 40 kg:
⇒( t + u) / (2) = 40 → t + u = 80.......(2)
The average weight of U and V is 36 kg:
⇒(u + v) / (2) = 36 ⇒ u + v = 72........(3)
Subtract equation (2) from equation (1):
⇒(t + u + v) - (t + u) = 126 - 80
⇒v = 46
v = 46 into equation (3):
⇒ u + 46 = 72 ⇒ u = 26
The weight of U is 26 kg.