Question

Jamal has a drawer containing 6 green socks, 18 purple socks, and 12 orange socks. After adding more purple socks, Jamal noticed that there is now a 60% chance that a sock randomly selected from the drawer is purple. How many purple socks did Jamal add?

A 6

B 9

C 12

D 18

E 24

Answer 1

Answer:

B 9

Step-by-step explanation:

We have 6 green socks, 18 purple socks, and 12 orange socks.

Adding more purple sock means 6 green socks, 18+x purple socks, and 12 orange socks.

We have a  probability of 60% of getting a purple sock.

P( purple) = number of purple socks / total

.60 = (18+x) / (6+18+x+12)

.60 = (18+x) / (36+x)

Multiply each side by 36+x

21.6 +.6x = 18+x

Subtract 18 from each side

3.6x +.6x = x

Subtract .6x from each side

3.6x = .4x

Divide each side by .4

9 =x

Jamal added 9 purple socks