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

Given:

22 gallons of 16% ammonia

24% ammonia

Find:

Number of gallons of water to remove

Solution:

Let n = number of gallons needed to obtain 24% ammonia

22 gallons (0.16) = n (.24)

N = 14.67 gallons of water

Answer 2

Answer:

The equation used to express n is:

$3.52=\dfrac{24}{100}\times (22-n)$

i.e. $352=24(22-n)$

step-by-step explanation:

initially we are given 22 gallons of solution that has  16% of ammonia solution.

i.e. it has $\dfrac{16}{100}\times 22=3.52$ gallons of ammonia.

Now we are asked to find how much gallons of water is to be removed to obtain a 24% ammonia solution i.e. we are asked to find the value of 'n'.

As we have to just remove water that means the amount of ammonia is same in the new solution i.e. in (22-n) gallons mixture.

i.e. $3.52=\dfrac{24}{100}\times (22-n)$

$24\times (22-n)=352\\\\24\times 22-24n=352\\\\528-24n=352\\\\528-352=24n\\\\176=24n\\\\n=7.3333$

Hence, the equation used to find n, the number of gallons of water he should remove is:

$3.52=\dfrac{24}{100}\times (22-n)$

i.e. $352=24(22-n)$