Determine whether each statement below is True or False.
Explain briefly if the statement is true, give a counterexample if it is false.
a) if 2 and 3 are factors of a number, then 12 must be a factor of that number.
b) if 2 or 5 are factors of a number, then 10 must be a factor of that number.
c) if 15 is a multiple of a number, then 45 must be a multiple of that number.
