A.
In a family with eight children, what is the probability there are at least six boys?
(Hint: Add the three probabilities for either six, seven, or eight boys.)
0.00390625
b. 0.109375
C. 0.03125
d. 0.1445

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!

:)

the answer is d

Step-by-step explanation:

a) Not replaced

Yellow marker First - Then Blue Marker  =

(1/10)(1/9)  =  1/90

b) Replaced

(1/10) (1/10)  = 1/100

Answer   "C"