Answer:
There are 190 ways to choose this pair of children
Step-by-step explanation:
Total number of students at summer camp = 20
Tatiana wants to choose a pair of students to lead the way
Number of students in a pair = 2
We are supposed to find In how many ways can Tatiana choose this pair of children
So, We will use combination
Formula :[tex]^nC_r=\frac{n!}{r!(n-r)!}[/tex]
n = 20
r= 2
So,[tex]^nC_r=\frac{n!}{r!(n-r)!}=\frac{20!}{2!(20-2)!}=190[/tex]
Hence There are 190 ways to choose this pair of children