Mr. duc asked to set up 450 chairs in a large hall. Perry puts 20 chairs in each row. He has already set up 15 rows of chairs
Each row consists of 20 chairs
He already set up 15 rows
So number of chairs he already set up = chairs in each row * number of rows
20 * 15 = 300
So , he already set up 300 chairs
Total chairs to set up is 450
Remaining chairs to set up = 450 - 300 = 150
So, 150 more chairs to set up