Question

The average weight of David, Esther, and Henry is 42.6 kg. Esther is twice as heavy as Henry. David is 5.2 kilograms lighter than Esther, what is Esther's weight?

Answer 1

53.2 kg

Explanation:

Let E represent Esther's weight. Then Henry's weight is E/2, and David's weight is E-5.2. Their average weight is ...

((E-5.2) + E + (E/2))/3 = 42.6

2.5E -5.2 = 127.8 . . . . . . . . . . multiply by 3, simplify

2.5E = 133 . . . . . . . . . . . . . . . . add 5.2

E = 133/2.5 = 53.2 . . . . kg

Esther's weight is 53.2 kg.