+0  
 
0
110
1
avatar+76 

1. There are five $5 and three $10 bills in a bag. A person reaches in and pulls out two bills. What is the probability of the sum of the bills will be $10, $15 or $20?

 

Thank You!

 

~Indian Tech Support

MrPatel  Mar 31, 2017
Sort: 

1+0 Answers

 #1
avatar+89750 
+2

Hello Mr Patel :)

 

1. There are five $5 and three $10 bills in a bag. A person reaches in and pulls out two bills. What is the probability of the sum of the bills will be $10, $15 or $20?

 

5,5,5,5,5,  10,10,10           8 notes altogether.

 

$10=$5+$5

\(P(5,5)=  \frac{5}{\not{8}^2}\times \frac{\not{4}^1}{7}=\frac{5}{14}\)

-----------------------------------------

$15    =   $5+$10    or     $10+$5

 

\(P(5,10)=  \frac{5}{8}\times \frac{3}{7}=\frac{15}{56}\\ P(10,5)=  \frac{3}{8}\times \frac{5}{7}=\frac{15}{56}\\ \text{P(sum of 15)}=\frac{30}{56}=\frac{15}{28} \)

-----------------------------------------

 

You can do the $20 yourself I think :)

Melody  Mar 31, 2017

21 Online Users

avatar
We use cookies to personalise content and ads, to provide social media features and to analyse our traffic. We also share information about your use of our site with our social media, advertising and analytics partners.  See details