Well, we do not know how many colored marbles they are, so let's represent it with y.
The question says that there are 32 more plain marbles than colored. That can be represented as 32 + y
The total number of marbles is 180. So that will be;
32+y=180
subtract 32 from 180;
y=180-32
y=148
So there are 148 colored marbles. Hope i helped. Have a nice day.