A student prepares for an exam by studying a list of 10 problems. She can solve 8 of them. For the exam, the instructor selects

Question

4 years ago

6

7 questions at random from the list of 10. What is the probability that the student can solve all 7 problems on the exam

1 answer:

lianna [129] · Answer 1 · 2021-12-26T21:21:40+03:00

Answer:

Probability to solve 7 problem will be equal to $\frac{1}{15}$

Step-by-step explanation:

It is given total number of question = 10

She can solve 8 of them from 10 questions

We have to find the probability that she can solve 7 question

Probability will be equal to ratio of favorable outcome to total sample space

Favorable outcome will be equal to $^8c_7$

Total sample space $=^{10}c_7$

So probability will be equal to $P=\frac{^8C_7}{^{10}C_7}=\frac{6}{90}=\frac{1}{15}$

So probability to solve 7 problem will be equal to $\frac{1}{15}$