2/5 x 10/7

To do this problem zall you need to do is multiply the denominators and the numerators together. (2 x 10) and (5 x 7) and then you divide the top and bottom by a common factor until it can't be reduced any more.

Or if you don't want to multiply 'big numbers' you can already start dividing:

\frac25 \times \frac{10}{7}

Ten, divided by 5, gives 2.

\frac{2}{\cancel{5}} \times \frac{\cancel{10}^2}{7}

Then, multiply the numerators, giving:

\frac{4}{7}

Now the question is... can this fraction be further simplified?