There were some rows of chairs in a tuckshop. Each row had 9 chairs. When Sabrina brought in 5 extra chairs and rearranged all the chairs, there were 4 chairs in each row and 5 more rows than before. How many chairs were there at first?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 5 |
Value |
9 |
4 |
Total value |
9 u |
4 u + 20 |
If another 5 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 + 5 = 4 u + 20
9 u - 4 u = 20 - 5
5 u = 15
1 u = 15 ÷ 5 = 3
Number of chairs at first
= 9 u
= 9 x 3
= 27
Answer(s): 27