Hi, my son has come home with some homework, which i have not come across before with him, I will give 3 examples:-

Find the number below 50, a multiple of 4 the sum of its didgits is 5

a 2 - digit number a multiple of 7 the product of it's digits is 16

a square number below 50, the sum of its digits is 9

I was hoping someone can explain these to me so I can explain to my son thank you:-)