A wallet containing 5 five dollar bills, 7 ten dollar bills, 8 twenty dollar bills is found and returned to its owner the wallets owner, will reward the finder with one bill drawn randomly from the wallet, what is the probability that the bill drawn will be a 20 dollar

The probability is 2/5 that a $20 bill will be drawn from the wallet.

Step-by-step explanation:

There are 20 total bills in the wallet (5 $5, 7 $10, and 8 $20, 5+7+8=20). So if the finder and returner of the wallet was to be given one of the bills drawn from the wallet there would be an 8/20 chance the owner of the wallet would pull a 20. That's because there are 20 total bills in the wallet and 8 of them are $20.  

Simplifying 8/20... 8/20= 4/10= 2/5.

So, there is a 2/5 chance that a $20 bill will be pulled out of the wallet.

Hope this helps!