There were some rows of chairs in a school field. Each row had 10 chairs. When Usha brought in 4 extra chairs and rearranged all the chairs, there were 6 chairs in each row and 2 more rows than before. How many chairs were there at first?
| |
First
arrangement |
Second
arrangement |
| Number |
1 u |
1 u + 2 |
| Value |
10 |
6 |
| Total value |
10 u |
6 u + 12 |
If another 4 chairs are added in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
10 u + 4 = 6 u + 12
10 u - 6 u = 12 - 4
4 u = 8
1 u = 8 ÷ 4 = 2
Number of chairs at first
= 10 u
= 10 x 2
= 20
Answer(s): 20
