is there a common multipple for 116, and 145? Can 116/145 be reduced or simplified? I have been agonizing for an hour over this. Please show me the answer.

There is always a common multiple, the product of the two numbers.

However look for a smaller one by factoring each.
116 = 2*58 = 2*2*29
145 = 5*29
so we need
29 and 5 and 2 and 2
= 580
check:
580/116 = 5
580/145 = 4 good
Well, we already know we can divide top and bottom of the fraction by 29 to simplify it.