Question

The average of a b c is 45 kg if the average of a and b is 40 kg and that of b and c is 43 kg find the weight of b

Answer 1

Answer:

weight of b is 31 kg

Step-by-step explanation:

given (a + b + c) / 3 = 45 kg

==> a + b + c = 135 kg   ----- (eq 1) (∵ 45 × 3)

given a + b / 2 = 40 kg

==> a + b = 80 kg

==> a = 80 - b

substitute in eq 1

80 - b + b + c = 135

c = 135-80

==> c = 55

given b + c / 2 = 43 kg

==> b + c = 86 kg

==> b = 86 - 55 (∵ c = 55)

==> b = 31 kg