Question

Medal
- 4 fraternal twins! Because there are four babies in the womb, the technician is unable to tell the gender of the babies.
(a) Find the probability that the quadruplets will all be boys. Express your answer as a fraction or an exact decimal - do not round.


(b) What is the probability that the couple will have 1 boy and 3 girls?


(c) What is the probability that the oldest three children will be female?

Answer 1

same as the probability that if you toss 4 coins they all come up head

Answer 2

\[\frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}=\left(\frac{1}{2}\right)^4=\frac{1}{16}\]

Answer 3

is that part a?

Answer 4

yes part A

Answer 5

(b) What is the probability that the couple will have 1 boy and 3 girls?
toss four coins
what is the probability you get 1 head and 3 tails?

Answer 6

1/3

Answer 7

hmm no

Answer 8

i am assuming you made that number up
lets compute it
the experiment has \(2^4=16\) possible outcomes, that will be your denominator (not 3)
the numerator is the number of ways you can choose one item from a set of 4
sometimes written as \(_4C_1\) or as\(\binom{4}{1}\)
or we can list all the possible outcomes if you like

Answer 9

bggg gbgg ggbg gggb

Answer 10

looks good
you got 4 of them
making your answer
\[\frac{4}{16}=\frac{1}{4}\]

Answer 11

so part b is 1/4

Answer 12

yes

Answer 13

what we do for part c

Answer 14

the probability the the first one is a girl is \(\frac{1}{2}\)
the probability the the second one is a girl is \(\frac{1}{2}\)
the probability the the third one is a girl is \(\frac{1}{2}\)
multiply these together to get the probability that all the first three are girls

Answer 15

how do you multiply fractions?

Answer 16

me? i use a calculator

Answer 17

but in general you multiply straight across just like you want to
\[\frac{a}{b}\times \frac{c}{d}=\frac{a\times c}{b\times d}\]

Answer 18

1 *1 =1 2*2 = 4

Answer 19

yeah but you have another \(\frac{1}{2}\) there

Answer 20

1/8

Answer 21

\[\frac{1}{2}\times \frac{1}{2}\times \frac{1}{2}\] right \(\frac{1}{8}\)

Answer 22

so the answer is 1/8?

Answer 23

oui

Answer 24

thank you :))))

Answer 25

yw