Problema Solution
Andy had 20% fewer marbles than Henry.l When Andy gave 80 marbles to Henry, the number of marbles he had left was half of what Henry had. How many marbles did Andy have in the beginning?
Answer provided by our tutors
let
a = the number of marbles Andy had in the beginning
h = the number of marbles Henry had in the beginning
Andy had 20% fewer marbles than Henry:
a = h - 0.20h
When Andy gave 80 marbles to Henry, the number of marbles he had left was half of what Henry had:
a - 80 = (h+80)/2
by solving the system of equations:
a = h - 0.20h
a - 80 = (h + 80)/2
we find:
a = 320 marbles
h = 400 marbles
click here to see the step by step solution of the system of equations:
Andy had 320 marbles in the beginning.