Question 432688
9. A vat contains 100 gallons of 50% brine solution.
 What is the greatest amount of water that can be added if the salt content cannot drop below 25%?
:
let w = amt of water
:
Write an amt of brine equation:
.50(100) = .25(x+100)
50 = .25x + 25
subtract 25 from both sides:
50 - 25 = .25x
25 = .25x
Now we can write this as an inequality
.25x =< 25
x =< {{{25/.25}}}
x =< 100 gal of water
this means, 100 or less gal of water can be added to keep the salt content at or above 25%