I am kind of stuck on this one

Each of two urns contains green balls and red balls. Urn I contains 10 green balls and 8 red balls. Urn II contains 3 green balls and 10 red balls. If a ball is drawn from each urn, what is P(red and red)?

(a) 23/18
(b) 10/27
(c) 40/117
(d) 18/31

The thing is, I know you may be thinking this is easy but is it 18/31? 18/31 makes sense but doesn't seem as complicated as it needs to be.

5 answers

add 10 + 8=18 then subtract that from all balls :D then it's 18/___(fill in the blank)
P(red&red) = 8/18 * 10/13 = 40/117

why does 18/31 make sense? That would be the probability if all the balls were in a single urn, but you have two separate events from two separate urns.
it is actually c 40/117 i took this test it makes no sense.
i chose the same answer i got thrown off by the and.

its supposed to be then.

not and.

what?
if only