Question

Grant plans to evaporate enough water from 22 gallons of a 16% ammonia solution to make a 24% ammonia solution. Which equation can he use to find n, the number of gallons of water he should remove?

Answer 1

Answer choices:

https://us-static.z-dn.net/files/d4b/ddd41892870e1b8d78accaf2b7dea9c5.png

Answer 2

24/100 is equal to 0.24, so looking at the right side of each answer choice doesn't really help much

so we'll focus on the left side. in order for the solution to be 24%, then (# of gallons ammonia) / (total # of gallons) must equal 0.24 or 24/100.

to calculate the numerator, multiply (16% ammonia) * (22 gallons)

for the denominator, take the original 22 gallons and subtract (n) gallons to be evaporated.