Answer :

Suzia
Of means multiply in math (most of the time). 
So multiply. 
2/5 x 7/10 = 14/50 divided by 2/2 = 7/25 
If you multiply the numerators 2x7 is 14 and is you multiply the denominators 5x10 is 50 so the fraction would be 14/50, but you could reduce so the answer would be 7/25 because 14 and 50 are even numbers.