1. You’re in NY and are trying to flag down a cab.
The chance of catching a cab on your street is
25% per minute of standing there.
What is the probability that you will still be there after:
i. 1 minute?
ii. 2 minutes?
b) What is the probability that you caught a cab in the 2nd minute?
c) What is the probability that you didn’t catch a cab in the 2nd minute?

2. What is the probability that you will still be there after:
P(C1) = 4/16
P(C1) = 1/4
P(S1 C2) = 3/16 C1 C2
P(C1) = 0.25
P(C2|S1) = 0.25
P(S1 S2) = 9/16 S1 S2
P(S1) = 0.75
P(S2 | S1) = 0.75
P(S1) = 3/4
What is the probability that you will still be there after:
i. 1 minute? 3/4
ii. 2 minutes? 9/16
b) What is the probability that you caught a cab in the 2nd minute? 3/16
c) What is the probability that you didn’t catch a cab in the 2nd minute? 13/16

3. The Jones family has 2 parents, 4 kids, 2 cats, 3 dogs
The Jones family has 2 parents, 4 kids, 2 cats, 3 dogs. 5 people/animals go on a walk. It is known that at least 1 parent went and at least 1 pet went. How many different scenarios are there for who went?

4. P1,P2 K1,K2,K3,K4 C1,C2,D1,D2,D3 (11 total)
0 animals
>0 animals
0 parents
>0 parents
1 parent
2 parents
Method 1: total – [(0P,0A) + (>0P,0A) + (0P,>0A)]
11c5 – [0 + 6c5 + 9c5] = – [ ] =
Method 2: (>0P, >0A) =
(1P,4A,0K) + (1P,3A,1K) + (1P,2A,2K) + (1P,1A,3K) +
(2P,3A,0K) + (2P,2A,1K) + (2P,1A,2K)
(2c1)*(5c4)*(4c0) + (2c1)*(5c3)*(4c1) + (2c1)*(5c2)*(4c2) + (2c1)*(5c1)*(4c3) +
(2c2)*(5c3)*(4c0) + (2c2)*(5c2)*(4c1) + (2c2)*(5c1)*(4c2) = 330