how many ways can a student select 2 books from a reading list of 10 books?

Explanation:

Step1: Determine the combination formula

The formula for combinations is (C(n,r)=\frac{n!}{r!(n - r)!}), where (n) is the total number of items, and (r) is the number of items to be chosen. Here, (n = 10) and (r=2).

Step2: Substitute values into the formula

[ \begin{align*} C(10,2)&=\frac{10!}{2!(10 - 2)!}\ &=\frac{10!}{2!×8!}\ &=\frac{10\times9\times8!}{2\times1\times8!}\ &=\frac{10\times9}{2\times1}\ & = 45 \end{align*} ]

Answer:

45