Question

A person tosses a coin 20 times. In how many ways can he get exactly 13 tails?

Answer 1

2^13 i think

Answer 2

you could set up a binomial probability table

Answer 3

2^13 sounds a bit too much, but I am not sure

Answer 4

77520 i believe is the binomial coefficient to 20 c 13

Answer 5

77520 is what im sticking with :)

Answer 6

that is even more than 2^13

Answer 7

lol ... it is :)

Answer 8

20c0 ways to get no tails
20c1 to get 1 tail
20c2 to get 2 tails etc ....

Answer 9

That sounds good for me

Answer 10

20C13 (or 20C7) looks good to me.