Can someone help me out with this?

We can do some "math" here, but let's use some logic, instead

If 3 counselors supervise 45 students......each counselor supervises 15 students

Then 10 of them would supervise 150 students......

There is a maximum of 150 students . Frst you had to do 45x3=90 add 45 =135 then its said 10 conulers & so far its been 9 and if you add 45 then it wldnt be right because ut asked fr 10 not 12, so then you divde 45 by 3 = 15 so you just add 135 + 15 = 150