Answer:
The chemist will mix 3 liters of the 5% acid solution and 2 liters of the 10% acid solution to get 5 liters of 7% acid solution
Step-by-step explanation:
Here, we are interested in finding the number of liters of each solution the chemist have to make use;
Let the number of liters of the 5% acid solution be x while the number of liters of the 10% acid solution be y
Mathematically;
x + y = 5 •••••••••(i)
Also, let’s work with the percentages now
( x * 5%) + (y * 10%) = (5 * 7%)
0.05x + 0.1y = 0.35 ••••••••(ii)
From i , x = 5-y
Substitute this into ii
0.05(5 -y) + 0.1y = 0.35
0.25 - 0.05y + 0.1y = 0.35
0.25 + 0.05y = 0.35
0.05y = 0.35 -0.25
0.05y = 0.1
y = 0.1/0.05
y = 2
But x + y = 5
x + 2 = 5
x = 5-2
x = 3