Question

you have three $1bills, four $5bills,and two $10 bills in your wallet.you select a bill at random.without replacing the bill,you choose a second bill at random.find p($5 then $10).

Answer 1

chance that first $5 is drawn - 4 out of 9(all bills). is like the ratio of $5 to total bills. then, chance to draw $10 when there is only 8 notes left - 2 out of 8(remaining bills).
the chance to draw a $10 is slightly higher the second time because there's less $5's you could get "accidentally"

Answer 2

first it's an unlikely event to get a $5 note, and ONLY if that was the case, another unlikely event HAS TO HAPPEN. so the unlikely event #2 ($10 note) is only our probability if it is WITHIN the first unlikely event.

http://sunburst.usd.edu/~mgamble/math342/PROBABILITY%20HELP%20SHEET.htm

in such multiple stage event, the probabililties are multiplied. because even if we had a guarantee of 100% for a second event, if the first event is only 40%, the total luck would be: 100% * 40% = 40%.

Answer 3

do you know what is the chance to pull a $5 from the original wallet ?

Answer 4

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