Posted by **Ana** on Thursday, January 28, 2010 at 10:53pm.

To win $1 million, you must draw two cards whose sum is nine from a stack of cards numbered 1 through 10. After the first draw, you replace the card and shuffle the stack again for the second draw. What is the chance that your two cards will have a sum of nine? I have to use the charts for the possibilities:

First Card

1 2 3 4 5 6 7 8 9 10

s 1

e 2

c 3

o 4

n 5

d 6

c 7

a 8

r 9

d 10

- Mathematicas -
**Reiny**, Thursday, January 28, 2010 at 11:19pm
there are 8 ways to get a sum of 9

1 8, 2 7, .... , 8,1

let's look at the prob of getting one of those pairs, the 1 8

prob of getting the 1 is 1/10.

since you are replacing the card, the prob of getting an 8 on the second draw is also 1/10

so the prob of getting the 1 8 combination is (1/10)(1/10) = 1/100

but there are 8 of those cases

so the prob of getting a sum of 9 when drawing 2 cards with replacement is 8/100 = 2/25

I want to play this game!

- Mathematicas -
**john **, Wednesday, December 21, 2011 at 11:46am
2/25

## Answer this Question

## Related Questions

- math - To win $1 million, you must draw two cards whose sum is nine, from a ...
- 4 grade - To win $1 million, you must draw two cards whose sum is nine from a ...
- math - To win $1 million, you must draw two cards whose sum is nine from a stack...
- Math - To win one million dollars, you must draw two cards whose sum is nine, ...
- math 4th grade - To win $1 million, you must draw two cards whose sum is nine, ...
- math - to win 1 million dollars,you must draw two cards whose sum is 9 , from a ...
- 4th - to win $1 millon you must draw two cards whose sum is 9 from a stack of ...
- math - I MUST DRAW TWO CARDS WHOSE SUM IS NINE, FROM A STACK OF CARDS NUMBERED ...
- Mathematicas - You are playing a card gam e with a full deck of 52 cards. You ...
- Math - If I have cards numbered 1 through 40 and I randomly draw 3 then replace ...

More Related Questions