the This problem uses permutation and combination. The formula to find the permutation is
while the formula to find the combination is
We need to know what type of problem the given is so that we can choose what equations we will be using on the equation above.
7. This problem is a combination problem since we want to know the total combinations of games that are possible for n = 14 and you have r = 6. The total combination is
Hence, there are 3003 ways you can choose six games.
8. We want to know how many ways a trumpet player can be arranged in a marching band lineup. We have n = 0 while our r here is also equal to 9 because we are arranging all the trumpet players in a different manner. Hence, using the permutation equation, we have
Hence, they can be arranged 362880 times.
9. This problem is a combination problem since we want to know how many possible arrangements can be done if a group that composed of n = 7, we arranged r = 4. Hence, using a combination equation, we have
Hence, they can be arranged in 35 ways.
10. Since we are dealing with arrangements, this is a permutation problem. We have n = 18 and we will arrange them in r = 3 ways. Hence, the total number of permutations possible is
Hence, they can be arranged in 4896 ways.
11. There are 12 letters present in the word INDIANAPOLIS. Since there are repetitions of letters, we will consider those. We have 3 I's, 2 A's, 2 N's. The possible permutation for the distinct arrangement of letters for INDIANAPOLIS can be computed as
The word INDIANAPOLIS can be arranged 19958400 without repetition of letters in the same placement.
12. This problem is a combination problem. We have n = 26 goldfishes and Ben wants to choose r = 5. Using the combination equation, we have