If the 2 prime numbers are odd then the product cannot be a square number because the only factors are the original prime numbers. If one of the prime numbers is 2 then the product will be an even number , but again the only factors will be 2 and the other prime number.
65*7=(1+1+1+1+1+1+1)=65+65+65+65+65+65+65=455 she did 65 sit ups every day for one week the expression is right there the answer to solve it is 455. :)