Question

When 200 gallons of oil were removed from a tank, the volume of oil left in the tank was 3/7 of the tank's capacity. what was the tank's capacity? (1) before the 200 gallons were removed, the volume of oil in the tank was 1/2 of the tank's capacity?

Answer 1

Explanation:

"When 200 gallons of oil were removed from a tank" algebraically looks like this:

V - 200.

"...the volume of oil left in the tank was 3/7 of the tank's capacity" algebraically looks like this:

3/7(V)

Therefore, the equation is

V - 200 = 3/7(V)

Begin by multiplying both sides by 7:

7(V - 200) = 3V and

7V - 1400 = 3V so

-1400 = -4V so

V = 350 gallons

That's if the volume of the oil in the tank was 3/7 of the tank's capacity.

For the other part of the problem, we set up the equation almost the same, except the 3/7 is a 1/2:

V - 200 = 1/2(V)

Multiplying both sides by 2 gives you

2(V - 200) = V and

2V - 400 = V so

-400 = -V so

V = 400