Question

How many different 4-question geometry quizzes can a teacher make if there are 7 different problems to test on?.

Answer 1

35 quizzes

Explanation:

We need to determine how many ways we can choose 4 questions out of 7 to make the quizzes.

We do this by using the formula
`\displaystyle nCr=(n!)/(r!(n-r)!)` which describes the number of ways we can choose
`r` objects given
`n` possible choices. So, if
`n=7` and
`r=4`, then:

`_4C_7=(7!)/(4!(7-4)!)\\\\_4C_7=(7*6*5*4!)/(4!*3!)\\\\_4C_7=(210)/(6)\\\\_4C_7=35`

Hence, the teacher can make 35 different geometry quizzes.