Question

How many different combinations of 3 books can Erika take on a trip if she has 5 books​

Answer 1

The number of different combinations of 3 books that Erika can take on a trip if she has 5 books is 10

Explanation:

Here we have the formula for combination given as follows;

`\binom{n}{r} = (n!)/(r!(n-r)!)`

Where n is the number of set elements = 5 and

r = Number of subset elements = 3

Therefore, plugging the values, we have;

`\binom{5}{3} = (5!)/(3!(5-3)!) = (120)/(6(2)) = 10`

Therefore, the number of different combinations of 3 books that Erika can take on a trip if she has 5 books = 10.

Answer 2

10 combinations

Explanation:

What we have to do is calculate the number of combinations of 3 in 5.

The formula for the combinations is:

nCr = n!/r!(n-r)!

in this case n = 5 and r = 3

replacing

5C3 = 5!/3!(5-3)! = 5!/(3!*2!)

5C3 = 10

So there are 10 combinations in which Erika can enjoy the books on her trip