Suppose we flip four coins simultaneously: a penny, a nickel, a dime, and a quarter. What is the probability that the penny and dime both come up the same?

polyyou Jun 15, 2020

#1**+5 **

so we have 16 orders and there are 2 orders that make the penny and dime both come up the same so the probability is 1/8

_{edited:reson oops I solved the wrong problem}

jimkey17 Jun 15, 2020

#3**+1 **

I'm not sure if you were right or wrong...

The question has some ambiguity so It's best to leave both answers.

hugomimihu
Jun 15, 2020

#2**+2 **

Does your question mean ONLY them come up the same or at LEAST?

SO.

I'll go with least.

There is a 1/2 chance dime gets same as penny.

If penny is heads, 1/2 dime head, etc.

If it's ONLY...

1/2 chance, and 1/2*1/2 chance that the other ones are NOT the same, so 1/8 of getting the same, if ONLY the penny and dime are the same.

hugomimihu Jun 15, 2020