Question

Please help me I really need this

Answer 1

56

Explanation:

8C5 = 56

Answer 2

8C5 = 56

Explanation:

The formula for nCk is ...

nCk = n!/(k!(n-k)!)

Then the value of 8C5 is ...

8!/(5!(8-5)!) = 8·7·6/(3·2·1) = 8·7

8C5 = 56

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Additional comment

The larger of the denominator factorials will cancel most of the factors of the numerator. The remaining denominator factors can be factored from the remaining numerator values to simplify the problem of doing the math by hand. Most graphing calculators and all spreadsheets can compute this function for you.

`(8!)/(5!\cdot3!)=(8\cdot7\cdot6\cdot5\cdot4\cdot3\cdot2\cdot1)/((5\cdot4\cdot3\cdot2\cdot1)(3\cdot2\cdot1))=(8\cdot7\cdot6)/(3\cdot2\cdot1)=(8\cdot7\cdot6)/(6)=8\cdot7`