Question

A drawer contains 4 red socks, 3 white socks, and 3 blue socks. Without looking, you select a sock at random, replace it, and select a second sock at random. What is the probability that the first sock is blue and the second sock is red?

Answer 1

Ok !!! so first of all .... probability of each event ..

case -1 .. probability of pulling blue sock

Answer 2

we will call this as s(b) ok ?

Answer 3

okay well is it 7/20?

Answer 4

no ...wait !!! think it again

Answer 5

no. of blue socks / total no. of socks .. can u find this ?

Answer 6

so 3 divided by 10...

Answer 7

yes right

Answer 8

0.3...

Answer 9

s(b)=\(\large{\frac{3}{10}}\)

Answer 10

now we will be moving on to case-2 that is of finding s(red)=s(r)
no. of red socks/total no. of socks

Answer 11

can u find s(r) ?

Answer 12

4/10

Answer 13

very correct ! good

Answer 14

s(b and r)=s(b)*s*(r) calculate this now

Answer 15

put the value of s(b)=3/10 and that of s(r) =4/10 multiply both
s(b)*s(r) .. what r u getting ?

Answer 16

wait ..think it again kmstevens10 ...
what is 3/10 *4/10 ?

Answer 17

\[\large{\frac{3}{10}*\frac{4}{10}}\]
try to calculate this again

Answer 18

12/100

Answer 19

right !!! so this is ur answer

Answer 20

that is not one of the answers they give me

Answer 21

What r the options

Answer 22

a. 3/5 b. 7/20 c. 3/25 d. 7/100

Answer 23

u can simplify 12/100 as 3/25

Answer 24

thank you.

Answer 25

\[\large{\frac{12}{100}=\frac{4*3}{4*25}=\frac{\cancel4 *3}{\cancel4*25}=\frac{3}{25}}\]

Answer 26

Thank you so much I get it now the next one can you help me with step by step that was a huge help
....

Answer 27

Two urns each contain green balls and blue balls. Urn I contains 4 green balls and 6 blue balls, and Urn II contains 6 green balls and 2 blue balls. A ball is drawn at random from each urn. What is the probability that both balls are blue?

Answer 28

again there are 2 cases : urn 1 and urn 2
urn 1 : total no. of balls = 10 no. of blue balls = 5

Answer 29

can u find s(urn1) ? for blue balls

\[\large{\frac{\textbf{no. of blue balls}}{\textbf{total no. of balls}}}\] in urn 1

Answer 30

18 balls correct?

Answer 31

no ! in urn 1 .. no. of blue balls = 5 . total no. of balls = 10

hence p(b)=5/10

Answer 32

ok so 5/10

Answer 33

yes now in urn II :
2/10 =s(b)

p(b)*s(b)=5/10 * 2/10

Answer 34

the whole problem is simplified down to 1/10

Answer 35

yes !!

Answer 36

thank you again!