Question

I need help ASAP please

Answer 1

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.

Answer 2

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.