Question

Please help me out here I'm a little stuck I think

Answer 1

Step-by-step explanation:

Given;

We are told that Matilda has 9 books and she wants to give 3 of these to her sister as a gift.

Required;

We are required to calculate how many different gifts are possible.

Step-by-step solution;

To determine how many gifts of 3 different books can be given out by Matilda, we will use the formula for combinations which is;

`_nC_r=(n!)/(r!(n-r)!)`

Therefore, to determine the combination of 3 books out of a total of 9;

`\begin{gathered} _9C_3=(9!)/(3!(9-3)!) \\ \\ _9C_3=(9*8*7*...*1)/(3*2*1(6*5*4*...*1)) \\ \\ _9C_3=84 \end{gathered}`

Therefore, there is a total of 84 different gifts

ANSWER

84