Problema Solution

D'Andre wants 14L of fruit punch that is 10% juice. At the store, he finds only punch that is 15% juice or punch that is 8% juice. How much of each should he purchase?

Answer provided by our tutors

x+y=14 ------- (1)

(15/100)x + (8/100)y= (10/100)14

15x+8y=140 ---------(2) 

mutiply equation (1) by -8

-8x-8y= -112 -----(3) 

add, (3) and (2):

7x= 28

x= 28/7= 4 lit

put this in equation (1): 4+y=14

so, y=10 lit.

 

so, 4 lits of 15% and 10 lits of 8%.