If the radius of this cylinder is doubled, its volume will be

twice as much
four times as much
eight times as much

four times as much

Step-by-step explanation:

The volume of a cylinder is given by :-

, where r is the radius and h is the height of the cylinder.

If the radius of this cylinder is doubled, then the radius of the new cylinedr will be:

R=2r

Now, the volume of the new cylinder is given by :-

Hence, If the radius of cylinder is doubled, its volume will be four times as much.

answer: h

step-by-step explanation:

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.