Question

Two pennies, a nickel, and a dime are placed in a cup. You draw a first coin and then a second coin.

a. Assuming you are sampling without replacement (i.e. you do NOT replace the first coin before taking the second), write the sample space of all ordered pairs of letters P, N, and D that represent the outcomes, and give the appropriate weights for each element of the sample space.



b. What is the probability of getting 11 cents?

Answer 1

a) {P1P2, P1N, P1D,P2P1, P2N,P2D,NP1,NP2,ND,DP1,DP2,DN}

PP=2/12 NP=4/12 DP=4/12 DN=2/12

b) 1/3

Explanation:

Let us call pennies by P1 and P2.

a)There are 12 possible outcomes as it is written above.

b)In order to have 11 cents we need a penny and the dime. There are 4 such possibilities (events). The total number is 12. So the probability is 4/12.