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  • A team of 4 students needs to be selected from a class of 9 students. However, two specific students, John and Sarah, cannot be on the team together. In how many ways can

A team of 4 students needs to be selected from a class of 9 students. However, two specific students, John and Sarah, cannot be on the team together. In how many ways can the team be formed?

Option: 1

50


Option: 2

84


Option: 3

70


Option: 4

60


Answers (1)

best_answer

Number of students = 9

Number of students to be selected = 4

Number of ways to select 4 students from 9 without John and Sarah together:

Selecting John:

We need to select 3 more students from the remaining 7 (excluding John and Sarah). This can be done in \mathrm{C(7,3)}ways.

Selecting Sarah:

Similarly, we need to select 3 more students from the remaining 7 (excluding John and Sarah). This can also be done in \mathrm{C(7,3)} ways.

\mathrm{\text { Total number of ways }=C(7,3)+C(7,3)=35+35=70 \text { ways. }}

Hence option 3 is correct.

 

Posted by

Ritika Kankaria

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