Makakuha ng detalyadong mga sagot sa lahat ng iyong tanong sa IDNStudy.com. Alamin ang mga detalyadong sagot sa iyong mga tanong mula sa aming malawak na kaalaman sa mga eksperto.

in how many ways can a student answer 5 out 8 question ?

Sagot :

This is an example of Combination.
Combination is the number of ways of selecting r items from a set of n.
Thus, the formula of Combination is
nCr = n!/r!(n-r)!

There are 8C5 ways that a student can answer 5 out of 8 questions.
Let's solve this.

8C5 = 8!/5!(8-5)!
       = 8! / 5!(3!)
       = (8×7×6×5!) / (5!×3×2×1)
       = (8×7×6) / (3×2×1)
       = 336 / 6
8C5 = 56 ways

Therefore, there are 56 ways that a student can answer 5 out of 8 questions.
This is a combination problem or simply where order doesn't matter
The formula is:
C=[tex]\frac{n!}{(n-r)!r!}[/tex]
where:
n=total number o objects
r=number of objects you need to answer
Substitute:
C=[tex]\frac{8!}{(8-5)!5!}[/tex]
C=[tex]\frac{8x7x6x5!}{3!5!}[/tex]
Cancel out the 6 and the 3! since they have the same value, and then cancel out 5! on both sides since they are the same, then you are left with:
C=8x7
C=56
Hope this helps =)