What is the probability of the next 6 flights; exactly four will be on time?
a) binom64 ⋅ (12)⁴ ⋅ (12)²
b) binom62 ⋅ (12)⁴ ⋅ (12)²
c) binom64 ⋅ (34)⁴ ⋅ (14)²
d) binom62 ⋅ (34)⁴ ⋅ (14)²