Question

If a, b, and c are numbers such that a/ b = 3 and b/c = 7, then (a+b)/ (b+c) is equal to which of the following?

7/2

7/8

3/7

1/7

21

Answer 1

Both a and c can be expressed in terms of b.

Answer 2

ok and how does that help?

Answer 3

Why don't you express a in terms of b, and c in terms of b, and substitute those expressions into the fraction?

Answer 4

That should give you a fraction in terms of b and numbers, and the answer choices suggest that the b's will fall out...