Hey! So this is pretty straightforward. You're given all the information already and now you just have to do some calculations.
60 + 30w = 480
You can start by subtracting 60 from both sides
30w = 420
Now you need to get w by itself so you have to divide both sides by 30 and you will end up getting
w = 14!
It will take him 14 weeks to save up