Eli has 8 black pens and 5 black pens in his desk drawer. He also has 3 yellow highlighters, 4 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 blue pen and he will not get a yellow highlighter?

Question

anonymous · Answer

Did you mean to say 8 blue pens?

anonymous · Answer

i meant to say 5 blue pens oops

anonymous · Answer

Just simplify 8/18 for the amount of blue pens. There are 18 total pens, and 5 are blue.

anonymous · Answer

Alright, in that case, the probability of choosing a blue pen is 5/13, and the probability of choosing a non-yellow highlighter is 1-3/12 = 3/4. So, multiply them, and teh answer is 15/52.

anonymous · Answer

@srossd thank you! could you help with another?

anonymous · Answer

Yeah, sure.

anonymous · Answer

using a twenty sided number cube, what is the probability that you will roll an even number or an odd prime number? the number 1 isn't an odd prime. round to three decimals

anonymous · Answer

Sorry, gotta go, but there are 10 even numbers and 7 odd primes, so it's 17/20 or 0.850