Question

Susan is 3 times as old as Paul and Paul is 3/2 times as old as Mary. What fraction of Susan's age is Mary?

Answer 1

Answer:

b) 2/9.

Step-by-step explanation:

Let Mary's age be x , then:

Paul's age is (3/2)x.

Susan's age =  3(3/2)x = 9/2 x.

So Mary is  2/9 the age of Susan.

Answer 2

Answer:

2/9

Step-by-step explanation:

We are given Susan (S) is 3 times as old as Paul (P) so S=3P.

And Paul (P) is 3/2 times as old as Mary (M) so P=(3/2)M.

What fraction of Susan's age is Mary?

So if S=3P and P=(3/2)M, then by substitution we have

$S=3(\frac{3}{2})M$

$S=\frac{9}{2}M$

Multiply both sides by the reciprocal of 9/2 resulting in:

$\frac{2}{9}S=M$

This says Mary is two-ninths the age of Susan.