Question

How do you evaluate `\frac { 2} { 5} \times \frac { 15} { 21}`=?

Answer 1

`2/7`

Explanation:

Start by multiplying across:

`2/5xx15/21=((2)(15))/((5)(21))=30/105`

Divide the top and bottom by 15 (a giant 1):

`(30-:15)/(105-:15)=2/7`