Question

16 is divided by the sum of a number q and 1. The result is 4. What is the number?

Answer 1

16/(q+1)=4
16/(q+1)=4 > Mult. both sides by (q+1)
16=4q+4 > Subtract 4 from both sides.
12=4q > Div. both sides by 4
q=3