Answer:
Step-by-step explanation:
This is a Combination (as in permutation vs combination) question the symbol (n r) refers to "n choose r". This is sometimes written as nCr
i.e the question is asking you to find how many combinations each will yield when you chose r items from n item without repetition and order does not matter.
I will only do the first question for you and you can just follow the same steps to solve the rest of the questions.
Recall that

Consider question a) we are given (5 1) or ₅C₁
we can see that n = 5 and r = 1
If we substitute this into the formula:
₅C₁ = (5!) / [ (1!)(5- 1)!]
= (5!) / [ (5- 1)!]
= (5!) / (4!)
= (5·4·3·2·1) / (4·3·2·1)
= 5
hence ₅C₁ = 5
No Answer
Step-by-step explanation:
There is no image so theres no way to help,
If you are going to ask this again make sure to put an image to get a better understanding, im sorry
Verified by FaZe DoDo
This is awfully general. Ruben has or does something. Whatever. Let's call that Whatever "r." Then the expression in question is "r+10."
Answer:
C.
Step-by-step explanation:
Location 1 is 20 feet ABOVE the sea level while Location 2 is 50 feet BELOW the sea level.
Location 1 would be 20
Location 2 would be -50
And think of the greater than and lesser than symbol as a alligators mouth it would go towards the bigger number so, -50 < 20, Location 1 is higher, is the answer.