There were some rows of benches in a hall. Each row had 7 benches. When Min brought in 6 extra benches and rearranged all the benches, there were 5 benches in each row and 4 more rows than before. How many benches were there at first?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 4 |
Value |
7 |
5 |
Total value |
7 u |
5 u + 20 |
If another 6 benches are added in the first arrangement, the total number of benches in the first arrangement and the second arrangement will be the same.
7 u + 6 = 5 u + 20
7 u - 5 u = 20 - 6
2 u = 14
1 u = 14 ÷ 2 = 7
Number of benches at first
= 7 u
= 7 x 7
= 49
Answer(s): 49