David has d books, which is 3

Cydney Seigerman, Magoosh Tutor

Hi Sonika :)

Good questions! We're describing the number of books for the three in terms of the number of books that David has, d.

Let's say that Jeff has j number of books. Since David has three times as many books as Jeff,

3j = d

Now, let's solve for j to describe the number of books Jeff has in terms of d:

3j = d
j = (1/3)d

We can check this is correct using actual values. Let's say that David has 12 books, which means that Jeff has 4 books:

j = (1/3)d
j = (1/3)*12
j = 4

Dec 9, 2016 • Reply