The chairs in the front half of the school auditorium are arranged in 9 rows of 20. The chairs in the back half are arranged in 5 rows of 25. Which expression could be used to find how many chairs are set up in the auditorium altogether?
A) 9 + 20 + 5 + 25
B) 9 x 20 x 5 x 25
C) 9 x 20 + 5 x 25 (Correct Answer)
D) (9 + 5) x (20 + 25)
Explanation:
The number of chairs in the front of the auditorium can be expressed as 9 x 20. The number of chairs in the back of the auditorium can be expressed as 5 x 25. In total, the number of chairs is the sum of these two expressions: 9 x 20 + 5 x 25.
Related Common Core State Standard: Operations & Algebraic Thinking: 5.OA.2
