What is 7/10 x 24/7?

$$\left({\frac{{\mathtt{7}}}{{\mathtt{10}}}}\right){\mathtt{\,\times\,}}\left({\frac{{\mathtt{27}}}{{\mathtt{7}}}}\right) = {\frac{{\mathtt{27}}}{{\mathtt{10}}}} = {\mathtt{2.7}}$$

You have two choices: Multiply directly or simplify first. 

Note that you can divide 10 and 24 by 2 -->

7/5 * 12/7

Now, cross out the 7's -->

1/5 * 12/ 1

12/5

You are left with 12/5 or 2.4.