Question

You fill a fish tank with 55 gallons of water on saturday. The water evaporates at a rate of 1.5 gallons per day you plan to add water when the tank reaches 49 gallons. When will you add water?

Answer 1

You will add water after 4 days.

Explanation:

Initial volume = 55 gallons

Final volume 49 gallons

Difference in volumes = 55 - 49 = 6 gallons

Rate of evaporate = 1.5 gallons per day

Number of days = n

Thus, in n days, 6 gallons of water evaporate, so

`1.5\cdot n=6\\ \\15n=60\ \ [\text{Multiply by 10}]\\ \\n=(60)/(15)\\ \\n=4\ days`

You will add water after 4 days.