In how many ways 2 students can be chosen from the class of 20 students?

180

190

240

None of these

The number of ways to choose 2 students from a class of 20 students is represented by the combination formula:

C(20,2) = 20! / (2! x (20-2)!)

where ! denotes the factorial function.

Simplifying the formula, we get:

C(20,2) = (20 x 19) / 2

= 190

So, there are 190 ways to choose 2 students from a class of 20 students.