Question

What is the value of 7C4?A). 35B). 840C). 2,520D). 5,040

Answer 1

A) 35

Step-by-step explanation:

The combination nCx can be calculated as:

`\text{nCx}=(n!)/(x!(n-x)!)`

Where n! = n(n-1)(n-2)...(2)(1)

So, to find 7C4, we need to replace n by 7 and x by 4 to get:

`7C4=(7!)/(4!(7-4)!)=(7!)/(4!(3)!)`

Therefore, 7C4 is equal to:

`7C4=(7\cdot6\cdot5\cdot4\cdot3\cdot2\cdot1)/((4\cdot3\cdot2\cdot1)(3\cdot2\cdot1))=(5040)/(24(6))=(5040)/(144)=35`

So, the answer is:

A) 35