Respuesta :
Answer:
0.22727
Step-by-step explanation:
Solution:-
- The math professor gives us a set of 12 problems and out of 12 problems he will give 6 on the final exam.
- The strategy is to determine in how many ways the math professor can select those 6 problems from the set of 12 problems.
- We have to select 10 questions such that all the exam problems were the one we studied.
- The total number of ways to select the 10 questions without restriction from pool of 12 question can be determined by use of combinations:
Total ways to select 10 out of 12:
12 C 10 = 66 ways to select 10 questions.
Number of ways to select 10 such that all 6 exam questions are there:
FIX Remaining 4: _ _ _ _
select 6 select other 4 : 6C4 = 15 ways
Hence, there 15 ways to select 10 such that all 6 exam problems are selected.
- The probability of all 6 problems are prepared for:
P ( All 6 ) = Favorable outcomes / Total outcomes
= 15 / 66
= 0.22727
