Answer:
There are many ways to solve this problem, here let's follow the hints
Probability of having exact 6 boys in 8 children:
8C6 x P(boys)^6 x P(girls)^2 = 8C6 x (1/2)^6 x (1/2)^2 =8C6 x (1/2)^8
Probability of having exact 7 boys in 8 children:
8C7 x P(boys)^7 x P(girls)^1 = 8C7 x (1/2)^7 x (1/2)^1 =8C6 x (1/2)^8
Probability of having exact 8 boys in 8 children:
8C8 x P(boys)^8 = 8C8 x (1/2)^8
Add these three, we have the solution
P = (8C6 + 8C7 + 8C8) x (1/2)^8 = (28 + 8 + 1) x (1/2)^8 = 0.1445
=> Option D is correct.
Note: 8C6, 8C7, 8C8 are combination notation.
Hope this helps!
:)
