Nines Awe wrote:
Alice and her Dad have a total weight of 117kg. Alice and her Mum weigh 88kg between them. Mum and Dad together weigh 161kg. What is the total weight of Mum, Dad and Alice?
its a nice trick if we want to take
2(a+b+c)=117+88+161=366
then (a+b+c)=183
I want to know what is the each one weight?
Actually, once you have spotted that the info given equates to two of each person, that way is much neater, however...
Alice + Dad = 117Kg
Alice + Mum = 88Kg
therefore
Dad is 29Kg (117 - 88) Kg heavier than Mum.
Dad + Mum = 161Kg
therefore
Mum is 66Kg ((161 - 29)/2) and Dad is 95Kg ((66 + 29) or (161 - 66)).
Alice is 22Kg (88 - 66).
Just to check, according to this method the total is 22 + 66 + 95, i.e. 183Kg, as in the (2A+2D+2M)/2 method .