A group of freshmen, juniors, and seniors

GRE Quant Problem Solving
1

A group of freshmen, juniors, and seniors are going on a school trip. The number of seniors is 60% of the number of juniors, which is 50% of the number of freshmen. If there are at least 150 students on the trip, then which of the following could be the number of seniors?

can anyone explain this.

This is how i construed.

S = 0.6 of J = 0.5 of F
ie 60% of j =50% of F

is this correct??

2

I would say that the wording of this question is a bit ambiguous
Because it can also be interpreted as:
s = 0.6 j
j = 0.5 f
s = 0.6 * 0.5 * f = 0.3f

It is not exactly clear if the “which” refers to “60% of the number of juniors” or “number of juniors”