Phill weighs 120 pounds and is gaining ten pounds each month. Phil weighs 150 pounds and is gaining 4 pounds each month. How many months, m, will it take for Bill to weigh the same as Phil?

5 months

Step-by-step explanation:

You had a typo and said that Phil weighed both amounts so I'm assuming that the second amount is Bill's weight

We can use LCM for this

So lets make a list for both of them

Phil:120, 130, 140, 150, 160, 170, 180, 190, 200

Bill: 150, 154, 158, 162, 166, 170, 174

As you can see here, after 5 months, they will have the same weight.

We can check our work to.

lets do 120+(10*5)=170

and 150+(4*5)=170

I hope this makes sense