x=number of grandkid
First find how many grandkids they can afford to buy souvenirs for. The prices of souvenirs for each grandkids will be (2+0.5) since they are each going to get a magnet and a key chain. The grandparents also want 5 magnets so you have to account for another 5($2)=$10.
x(2+0.5) + 5(2) <= 60
<= is the closest I can type to a "less than or equal to" sign
I'm going to let you try to solve for x, if you have any trouble let me know.
Once you evaluate this equation, you will have the number of grandchildren they are able to buy souvenirs for.
The question asks for the number of magnets and key chains bought, so you have to remember that they bought an additional 5 magnets for themselves.