math
posted by Ed .
I have three packages whose total weight is 60 kg. If the two heaviest packages weigh 50 kg together, and the two lightest weigh 25 kg together,
what is the weight, in kg, of the heaviest package?

Heaviest  h
middle  m
lightest  l
h+m+l = 60 (1)
h+m = 50 (2)
m+l = 25 (3)
(1)  (2) > l = 10
(1)  (3) > h = 35
then m = 15
check: total = 60
lightest + middle = 25
heaviest + middle = 50 CHECK!