Posted by **Jen** on Wednesday, July 27, 2011 at 9:49am.

Mary purchased a package of 13 different plants, but she only needed 9 plants for planting. In how many ways can she select the 9 plants from the package to be planted?

- Math -
**Reiny**, Wednesday, July 27, 2011 at 10:07am
This would be an example of the C(n,r) that I explained in a few posts below.

You are choosing 9 from the 13, and the order really does not matter, so

C(13,9) = 13!/(9!4!) = 715

look for a key labeled _{n}C_{r} on your calculator

press

13

2ndF

_{n}C_{r}

9

=

you should get 715

- Math -
**Jen**, Wednesday, July 27, 2011 at 12:25pm
yea i was having a problem because the calculator i have doesnt have the F button, but thanks for helping me...it was very confusing to me...

## Answer this Question

## Related Questions

- geometry - Show all work. Mary purchased a package of 15 different plants.but ...
- Math - Question 1 : We would like to test 3 different treatments on a particu- ...
- Math - green park is adding 236 plants this spring. One hundred fifty of them ...
- math - Lucy has 40 bean plants,32 tomato plants,and16 peppers plants.She wants ...
- 6th grade math - liam is planting 30 bean plants and 45 pea plants in his garden...
- Math - We would like to test 3 different treatments on a particular type of ...
- math - One package of water plants is recommended for 3000 cubic centimeters of ...
- math - One package of water plants is recommended for 3000 cubic centimeters of ...
- math - Gwen was planting tomato plants in a row 6 2/3 yards long. She put the ...
- Bio - Which term does not describe one of the three categories into which land ...