Answer:
Step-by-step explanation:
The probability that Boris is assigned a moderate-difficulty question would be the ratio of number of moderately difficult questions to the number of total questions available.
The quiz consists of 2 high difficulty, 7 moderate difficulty, and 6 low difficulty questions. That is 2 + 7 + 6 = 15 questions in total.
and
the number of moderately difficult questions is 7
Hence the probability would be 7/15