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?

MrCreative
Aug 26, 2018

#1**+1 **

[4! /2!*2!] / 2^4 =0.375 x 100 =37.5% - prob. of the penny and the dime coming up the same.

Guest Aug 26, 2018

#3**+1 **

The nickel and quarter are irrelevant in this problem.

So the probability of both the penny and the dime landing on heads is 1/4, and the probability of them landing on tails is also 1/4. The probability of them coming up the same is thus 1/2.

Guest Aug 26, 2018

#4**+3 **

We have 16 possible outcomes [2 for each coin = 2^4 = 16 ]

The penny and dime can both show tails...and there will be 2 * 2 = 4 outcomes for the other two coins

or

The penny and dme can both show heads...and there will be 2 * 2 = 4 outcomes for the other two coins

So....P ( penny and dime have the same results ) = is [ 4 + 4 ] / 16 = 8 / 16 = 1 / 2

CPhill
Aug 26, 2018