A fair 2 sided coin is flipped 6 times. What is the probability that tails will be the result at least twice, but not more than 5 times? Choose the correct choice from the following options.
A) 5/8	B) 3/4	C) 7/8	D) 57/64	E) 15/16
It would be easier to calculate the probability of opposite event and subtract it from 1.   Opposite event: 0 tail, 1 tail, 6 tails.   Probability of getting no tails: 1/2^6=1/64   Probability of getting 1 tail: 67/81∗1/2^6=6/64, we must multiply by 67/81 or by 6 as tail can occur for any flip from 6, hence in 6 ways;   Probability of getting 6 tails: 1/2^6=1/6^4   P=1−(1/64+6/64+1/64)=56/64=7/8   Answer: 7/8.
<result>C</result>
A fair 2 sided coin is flipped 6 times. What is the probability that tails will be the result at least twice, but not more than 5 times?