A box contains 20 cards, numbered 1-20. You select a card and after replacing it,select another card. Find the probability of drawing a 1 and then a 19?

Question

anonymous · Answer

Off the top of my head, it sounds like 20*20:1

anonymous · Answer

well..that's kinda what i was thinking. i was thinking about multypling 1/20*1/20

anonymous · Answer

no, its 1/10*1/9 half the cards are even

anonymous · Answer

and then i get 1/90

anonymous · Answer

Heheh...it goes both ways

It's either 1 in 400 that you will, or it's 400 to 1 that you won't.  :-)

But the wording of the question makes it 1:400, or 1/400 that you'll succeed.

anonymous · Answer

oh sorry, I misread the question, 1/20 *1/20..the prob of getting a 1 is 1/20 and prob of getting a 19 is 1/20

anonymous · Answer

its okay and yeah that was what i was thinking at first