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2 votes
I need help ASAP please

I need help ASAP please-example-1
User Vadim
by
7.6k points

2 Answers

2 votes

Answer:

Choice D is correct answer.

Explanation:

We have to find number of ways to choose students to go to library.

From question statement , we observe that

Numbers of students = n= 10

Number of selected students = r = 3

Order doesn't matter.

Hence,we use the formula of combination to solve this question.


^(n) C_(r) = n!/(n-r)!.r!

putting the values of n and r in abobe formula ,we get


^(10) C_(3) = 10!/ (10-3)!.3!


^(10)C_(3) =10!/7!.3!


^(10) C_(3)= 120 ways

Hence, there are 120 ways to choose the students to go to library.



User Dumitrescu Bogdan
by
6.8k points
6 votes

Answer:

The correct option is D. The total number ways to select 3 student from 10 stents is 120.

Explanation:

The total number of students is 10.

The number of selected students is 3.

According to the combination formula.


^nC_r=(n!)/(r!(n-r)!)

Where, n is total possible values and r is number of selected values.


^(10)C_3=(10!)/(3!(10-3)!)


^(10)C_3=(10* 9* 8* 7!)/(3* 2!* 7!)


^(10)C_3=120

Therefore option D is correct.

User Smith Dwayne
by
6.8k points