- #1
Juntao
- 45
- 0
help with 2 "simple" probability probs
Ok, I'm having a hard time with probability.
First problem.
A restaurant offers a choice of 4 appetizers, 14 entrees, 6 desserts, and 5 beverages. How many different meals are possible if a diner intends to order only three courses? (consider the beverage to be a course)
Maybe I'm making this problem harder than it is. I want to do 4*14*6*5 = answer, but that would only be for a 4 course meal, not a three course meal...right?
Second problem
Residents of a condominium have an automatic garage opener that has a row of 8 buttons. Each garage door has been programmed to respond to a particular set of buttons being pushed. If the condominium has 250 families, can residents be assured that no two garage doors will open on the same signal? If so, how many additional families can be aded before the 8-button code becomes inadequate? *Note* The order in which the buttons are pushed is irrelevant.
I was thinking maybe the answer would be like 250^8, but that doesn't seem right to me. Since the order doesn't matter, 8 buttons such as 12345678 would be same thing as 87654321.
So I was thinking maybe answer was 8! ?
Ok, I'm having a hard time with probability.
First problem.
A restaurant offers a choice of 4 appetizers, 14 entrees, 6 desserts, and 5 beverages. How many different meals are possible if a diner intends to order only three courses? (consider the beverage to be a course)
Maybe I'm making this problem harder than it is. I want to do 4*14*6*5 = answer, but that would only be for a 4 course meal, not a three course meal...right?
Second problem
Residents of a condominium have an automatic garage opener that has a row of 8 buttons. Each garage door has been programmed to respond to a particular set of buttons being pushed. If the condominium has 250 families, can residents be assured that no two garage doors will open on the same signal? If so, how many additional families can be aded before the 8-button code becomes inadequate? *Note* The order in which the buttons are pushed is irrelevant.
I was thinking maybe the answer would be like 250^8, but that doesn't seem right to me. Since the order doesn't matter, 8 buttons such as 12345678 would be same thing as 87654321.
So I was thinking maybe answer was 8! ?