Student A is 15 years old. Student B is one-third older. How many years ago was student B twice as old as student A?
A) 5
B) 7
C) 9
D) 10

D

Step-by-step explanation:

one third of 15 is 5

15 + 5 = 20

Student B is 20 years old, 5 years older than student A

10 years ago, Student B was 10 and Student A was 5.

the dimensions are:

step-by-step explanation:

we want to find the dimensions of a rectangular box with volume of

we factor to obtain;

we rewrite the rightmost factor to obtain;

recall that:

we apply difference of two squares formula to obtain;

hence the dimensions are