Question

Eli has 7 black pens and 5 blue pens in his desk drawer. He also has 3 yellow highlighters, 2 green highlighters, and 5 pink highlighters in his pencil case. If he chooses one pen and one highlighter without looking, what is the probability that he will get a black pen and he will not get a green highlighter?

Answer 1

@rational

Answer 2

consider the events separately

Answer 3

` 7 black pens and 5 blue pens`

what is the probability that he will get a black pen ?

Answer 4

7/12?..

Answer 5

yep

Answer 6

Yes.

` 3 yellow highlighters, 2 green highlighters, and 5 pink highlighters `

whats the probability that he will get something other than green ?

Answer 7

2/10 for highlighters

Answer 8

careful, we don't want green

Answer 9

it's 8/10

Answer 10

so 4/5

Answer 11

Correct! multiply both

Answer 12

I mean 8 out 10

Answer 13

7/15?

Answer 14

that's it?

Answer 15

probability that `he will get a black pen` and `he will not get a green highlighter` =

\[\dfrac{7}{12}\times \dfrac{4}{5} \]

Answer 16

yeah that simplifies to
\[\large \dfrac{7}{15}\]

Answer 17

thats it, good job !

Answer 18

okay, thanks!