For this question, i already solve the part a and part b. For the part c, i try to solve it but i cant get the answer that given. Can someone explain to me? How to do the part c. Thanks!(adsbygoogle = window.adsbygoogle || []).push({});

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Permutation and combination

**Physics Forums | Science Articles, Homework Help, Discussion**