Question

Solve by simplifying the problem. There are 18 students in Mr. Alvarez’s art class. Throughout the year, every student must pair up with every other student to complete a project. How many projects will be finished?

A. 149 projects

B. 153 projects

C. 171 projects

D. 135 projects

Answer 1

answer will be 153

Answer 2

17 + 16 + ... + 2 + 1 = ?

Answer 3

18 student and they each will do project with each other
ie in combination of 2 people
so
We will go for combination
18 c 2
\[18! / (18-2)! \times 2!\]

Answer 4

Thank you

Answer 5

17 + 16 + ... + 2 + 1 = \(\dfrac{17 \cdot 18}{2} = 153\)