Task: Question Answering
Input (English): Problem: a fair 2 sided coin is flipped 7 times. what is the probability that tails will be the result at least twice, but not more than 7 times ?
Options: a. 119 / 128, b. 120 / 113, c. 114 / 210, d. 121 / 141, e. 104 / 117
Output (English): a