Answer
$\frac{1}{196}$
Work Step by Step
We know that $probability=\frac{\text{number of favorable outcomes}}{\text{number of all outcomes}}$
The number of all outcomes is $(50)(50-1)(50-2)=50\cdot49\cdot48=117600$, because the first chocolate can be any, the second can be apart from the first one, the third can be any apart from the first two.
The number of good outcomes is $30\cdot5\cdot4=600$ because the first person is any solid piece, the second is any cherry piece, the third is any cherry piece that is not the second one.
Thus probability$=\frac{600}{117600}=\frac{1}{196}$
