<PRE><B>Question 1120969</B>
spark drug store keeps two acid solutions on hand to fill orders for its customers. 
one solution is 10% acid and the other is 25% acid.
 an order received for 15 liters of 12% acid solutions.
 how much 10% acid solutions and how much 25% acid solution should be combined to fill this order
:
let x = amt of 25% solution required, then
(15-x) = amt of 10%
:
.25x + .10(15-x) = .12(15)
.25x + 1.5 - .10x = 1.8
.25x - .10x = 1.8 - 1.5
.15x = .3
x = .3/.15
x = 2 liters of the 25% solution, 

I&#39;ll let you find the amt of 10% solution
Check your solution in original equation </PRE>