Find the probability that when a couple has fourfour children, at least one of them is a girlgirl. (assume that boys and girls are equally likely.)

A - at leats one is a girl

B - none is a girl

This is a case of binomial probability, with n=4 and p=0.5.

Note that P(at least one of the four children is a girl) = 1 - P(no girls among 4 children).

P(no girls among 4 children) = binompdf(4,0.5,0) = 0.0625

Then P(at least one of the four children is a girl) = 1 - 0.0625 = 0.94.

answer: - (a)

(b) 88 seats

step-by-step explanation:

given: in an auditorium, there are 22 seats in the first row and 28 seats in the second row.

thus first term=

second term=

the number of seats in a row continues to increase by 6 with each additional row.

⇒d= 6

a) given formula :

b)   let the number of seats (n) = 12

substitute n=12 in the explicit rule formed in (a)

∴there are 88 seats in 12 rows.