After 75 gallons of oil are removed from a cylindrical thank, its level is lowered from 1/6 to 1/7 of its capacity. How many gallons should now be added to the tank to fill it?

See answer to previous post.

This one would be an excellent example for practice.

To solve this problem, we need to find the total capacity of the cylindrical tank.

Let's assume the capacity of the tank is C gallons.

According to the problem, after removing 75 gallons of oil, the level is lowered from 1/6 to 1/7 of its capacity.

This can be written as:

C - 75 = (1/7)C

To solve this equation, we can multiply both sides by 7 to eliminate the fraction:

7(C - 75) = C

7C - 525 = C

Now, we can simplify the equation by moving all the C terms to one side:

7C - C = 525

6C = 525

Dividing both sides of the equation by 6 gives us:

C = 525/6 = 87.5

So, the total capacity of the cylindrical tank is 87.5 gallons.

To fill the tank completely, we need to add the amount of oil necessary to reach the total capacity.

Since 75 gallons have already been removed, we need to add:

87.5 - 75 = 12.5

Therefore, you should add 12.5 gallons to fill the tank completely.