Oof, I was just about done with answering this question but I deleted it all by accident so I had to rewrite it.
Anyways, the first part of it is correct.
The second part of it is a bit harder. See, this is conditional probability, which uses the equation that I've attached below.
For Event A, you'll need the total boys / total students:
0.44166
For Event B, you'll need the total counters / total students:
0.83333
Now, plug these values into the equation. The weird U thingy is called "Union". It basically means "and".
P(A and B) / P(B)
P(0.44166 * 0.8333) / P(0.8333)
0.36803 / 0.8333
This is about 0.44165, or 53/120