If the radius of a cylinder is doubled and the height is tripled, what happens to the volume?
a)
it is multiplied by 6.
b)
it is multiplied by 12.
it is multiplied by 18.
d)
it is multiplied by 32

B

Step-by-step explanation:

Original volume = pi * r^2 * h

New r = 2*r

New h = 3*h

New Volume = pi * (2r)^2 *3*h

New Volume = pi * 4r^2 * 3 *h

New Volume = 4*3 * pi * r^2 + h

Conclusion

The New Volume = 12* the original volume

option 1 is correct.

step-by-step explanation:

y varies inversely with x and constant of variation is 4

the equation will be:

y = k/x

where k =4 so,

y = 4/x

if we put values of x of option 1 in the above equation and find values of y

y = 4/-2 => y =-2

y = 4/-1 => y = -4

y = 4/1 => y = 4

y = 4/2 => y =2

so, all the values of x and y are correct.

if we put values of x given in other options and find value of y we cannot find whole table satisfying the equation.

hence option 1 is correct.