What is the ratio for the volumes of two similar spheres, given that the ratio of their radii is 5:9?
A. 125:729
B. 25:81
C. 729:125
D. 81:25

Option A

Explanation:

the ratio of radii to volume is ^3 "to the third power"

so 5^3 : 9^3 would be the ratio for volumes

125:729

3/4 ÷ 3/4

step-by-step explanation:

basically divide any proper fraction with itself to fit the criteria.

so if we are using 3/4, then:

3/4 ÷ 3/4 = 1

so 1 is the quotient.

and the numerators for both these fractions is 3.   and if we divide the numerators:

3 ÷ 3 = 1

we see that quotient is equal to our original quotient as well.

you can first factor out the n to get n(1+5). we know that 1+5 is 6, so we just have 6n.