Question

I don't know at all please help me

Answer 1

Alrighty. 
First we need to make them all simplified. 
So simplified would be $\frac{9}{10}$ times $\frac{5}{4}$ times $\frac{5}{2}$.
Then we multiply the numerator and the denominator. The final answer is $\frac{225}{800}$
Simplified is $\frac{51}{160}$