Answer:
153
Explanation:
There are 18 students in a class.
They are required to pair up with every other student to complete a project throughout the year .
Now we are asked to find the no. of projects will be finished .
So, we will use combination
Formula :

No. of students (n)=18
No. of students in each pair (r)= 2
Substituting the values in formula :






Thus the no. of projects will be finished is 153