How much solution of each?

Question

Gabe​ Amodeo, a nuclear​ physicist, needs 60 liters of a 40​% acid solution. He currently has a 30% solution and a

60% solution. How many liters of each does he need to make the needed 60 liters of 40​% acid​ solution?

Answer 1

Let x be the amount of the 30% solution and

Y be the amount of the 60% solution

x+y=60 (60 being the total in liters)

Subtract t from both sides

x=60-y

.30x + .60y = 60(.40)

Substitute x=60-y

.30(60-y) + 60y = 60(.40)

Distribute

18-.30y+.60y=24

Combine like terms

18+.30y=24

Subtract 18 both sides

.30y=6

Divide by .30

y=20

Since x=60-y=60-20=40

To check

.30x + .60y = 60(.40)

.30(40)+.60(20)=60(.40)

12+12=24

24=24