Need help on this ASAP!!! A cup has 4 pencils, 3 black pens, 1 blue pen, and 5 red pens.
What is the probability of selecting a black or blue pen?

Question

Need help on this ASAP!!! A cup has 4 pencils, 3 black pens, 1 blue pen, and 5 red pens.
What is the probability of selecting a black or blue pen?

anonymous · Answer

@jdoe0001 can you help me??

math&ing001 · Answer

Probability of finding a black pen + Probability of finding a blue pen $$C _{13}^{3} + C _{13}^{1}$$

anonymous · Answer

so 4/13?

math&ing001 · Answer

Yeah so I would say. Btw forget about the second line I wrote.

anonymous · Answer

I need help on another one

math&ing001 · Answer

Ok i'll see if I can help, probability.has never been my strong point.

anonymous · Answer

A pair of dice is rolled. What is the probability that the sum of the two dice will less than 4 given that the first die rolled is a 2?

math&ing001 · Answer

Does your sum need to be (strictly less) or (less or equal) ?
For the first it'll be 1/6, for the second it'll be 2/6.

anonymous · Answer

Okay thank you.