There were some rows of chairs in a canteen. Each row had 9 chairs. When Kylie brought in 12 extra chairs and rearranged all the chairs, there were 6 chairs in each row and 4 more rows than before. How many chairs were there at first?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 4 |
Value |
9 |
6 |
Total value |
9 u |
6 u + 24 |
If another 12 chairs are added in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
9 u + 12 = 6 u + 24
9 u - 6 u = 24 - 12
3 u = 12
1 u = 12 ÷ 3 = 4
Number of chairs at first
= 9 u
= 9 x 4
= 36
Answer(s): 36