Six friends are at the school carnival. They all want to go on the same ride, but only three people can go on the ride at one time. How many different combinations of three riders are possible?

A.18
B.9
C.20
D.40

Question

Six friends are at the school carnival. They all want to go on the same ride, but only three people can go on the ride at one time. How many different combinations of three riders are possible?

A.18
B.9
C.20
D.40

anonymous · Answer

i think its A. but i would get a second opinion

anonymous · Answer

you are being asked for "6 choose 3" which is 
$$\frac{6\times 5\times 4}{3\times 2}=20$$

anonymous · Answer

hmm im split between 2 answers who should i go with?

anonymous · Answer

@satellite73 r u 100% sure?

anonymous · Answer

you should learn how to compute "n choose k" for yourself
it is written as $\binom{n}{k}$ or sometimes $_nC_k$