It takes 20 hours to fill the pool using the first hose. it takes 16 hours to fill the pool using the second hose. how long would it take if you used both?

8 hours

Step-by-step explanation:

Let x represent the time it takes if both are used.

The unit time it takes to fill the pool using the first house is 1/20 and also the unit time it takes to fill the pool using the second house is 1/16 , therefore:

1/16 + 1/20 = 1/x

=

=

Therefore

x =

Therefore, it takes 8 hours using both houses

8 and 8/9 hours

Step-by-step explanation:

The rate of filling for the first hose is (1 pool/20 hrs)

The rate of filling for the second hose is (1 pool/16 hrs)

Let t= time to fill pool using both hoses

1/120 + 1/16 = 1/t

Multiply both sides by 320 t  (which is 20*16)

300t/20 + 302t/16 = 320t/t

16t +20t = 320

36t = 320

t= 8.8888888 = 8 and 8/9  

answer: the answer is (b) amie should have multiplied

step-by-step explanation: given a sphere and a cylinder with same radius and height.

let, 'r' be the radius of the cylinder and sphere and 'h' be the height of the cylinder. according to the question,

r = h.

now, the volume of the sphere will be

and the volume of the cylinder will be

therefore, we have

thus, ammie should have multiplied the volume of the sphere

is only a line? i think so