A water pump takes 70 minutes to fill a tank. A larger pump can fill the same tank in 30 minutes.
How long will it take to fill the tank if both pumps are used?

A. 15 minutes
B. 21 minutes
C. 40 minutes
D. 50 minutes

21 minutes Option B

Step-by-step explanation:

1 min

Small --> 1/70

Big --> 1/30

Together --> 1/70 + 1/30 = 3/210 + 7/210 = 10/210 = 1/21

1 divided by 1/21 = 21

Thus, it's 21 minutes (B)

saving = more money

step-by-step explanation:

if you have 100 bucks, and you want to buy a candy bar, even if you have one at home, if you choose not to buy it, you save.

~courtney

according to the triangle sum theorem, all the angles in a triangle must add up to 180 degrees. if we know one angle is already 90, we do 180-90=90. the other 2 angles must add up to 90, exactly.

step-by-step explanation: