Probability - need the answers to know if im on the right track while practicing

1. in how many ways can a hockey team consisting of 11 players be chosen from a squad of 14 players

2. 80 disc marked with the numbers 1 to 80 are placed in a box and one disc is drawn from it. determine the probability that the number on the disc will be a multiple of 5

3. A bag contain 4 red marbles, 3 blue marbles and 7 green marbles. A marble is drawn from the bag. What is the probability that it will be a red marble.

4. In how many ways can one select a committee of four republicans, three democrats and two independents from a group of 10 distinct republicans, 12 distinct Democrats and 4 distinct independents?

Re: Probability - need the answers to know if im on the right track while practicing

A better idea, show us what you have done (to prove you have shown some effort) and we will check over it..,

Re: Probability - need the answers to know if im on the right track while practicing

Q1 sol

n/r!(n-r)!

14/11(14-11)

14*13*12/3 = 728

Q2 Not sure where to even sart

Q3 sol

4+3+7 = 14

1/14

Q4 sol

10/4(10-4) * 12/3(12-3) * 4/2(4-2)

10/4(6) * 12/3(9) * 4/2(2)

5040/24 * 1320/6 * 12/2

answer seem too big not sure if correct

Re: Probability - need the answers to know if im on the right track while practicing

Q1:

Q2: Every five numbers is a multiple of 5. Since 80 is divisible by 5, you have a chance of drawing a multiple of 5. But, in general, you need to find out how many multiples of 5 are among the numbers 1 to 80 (there are ). Then, the chances of drawing a multiple of 5 are .

Q3: Four of the fourteen marbles are red. So, you have a chance of drawing a red marble.

Q4: Use the exclamation mark for factorial.