So, let's multiply 2/5 by 7/10. The reason I know to multiply is because of the word "of". Of is a multiplication word, so let's multiply.
2/5×7/10=14/50
The reason I know that I could simplify it is because the numbers are both even, so they are able to get split.
14/50=7/25
7 is a prime number and 25 is not divisible by 7, so 7/25 is 2/5 of 7/10 in simplest form.
