What is 5/3 % 2/7 how do you solve this problem

Well first off, you asked "%" instead of the division-sign, which is very significant because "%" is used to find the remainder of something and is called a Modulus. 5/3 / 2/7 = ...
Well if you are dividing by a fraction, you can switch the numerator and denominator of the fraction in the denominator spot and multiply that value with the numerator.

(5/3) * (7/2) = (5 * 7) / (3 * 2) = 35 / 6

This would be the best answer you can get. As for a Modulus, if you say "5 % 3", the answer is 2 because after fitting in all the stacks of "3" into the number "5", you will have a remainder of 2. If it was 11 % 2, the remainder is 1 so the answer is 1 for that. If you weren't asking about Modulus, try to use "/" instead or the divisions-gin, ÷. Thank you.