In the school hall, chairs were arranged in rows of 13. During a function, 30 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 11. As a result, there were 4 more rows.
- How many chairs were there in the extra 4 rows?
- How many chairs were there in the school hall in the end?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 4 |
Value |
13 |
11 |
Total value |
13 u |
11 u + 44 |
(a)
Number of chairs in the extra 4 rows
= 4 x 11
= 44
(b)
Total number of chairs in the first arrangement
= 1 u x 13
= 13 u
Total number of chairs in the second arrangement
= 11(1 u + 4)
= 11 u + 44
If 30 chairs were included in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
13 u + 30 = 11 u + 44
13 u - 11 u = 44 - 30
2 u = 14
1 u = 14 ÷ 2 = 7
Number of chairs in the school hall in the end
= 7 x 13 + 30
= 91 + 30
= 121
Answer(s): (a) 44; (b) 121