In the school hall, chairs were arranged in rows of 11. During a function, 29 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 8. As a result, there were 7 more rows.
- How many chairs were there in the extra 7 rows?
- How many chairs were there in the school hall in the end?
| |
First
arrangement |
Second
arrangement |
| Number |
1 u |
1 u + 7 |
| Value |
11 |
8 |
| Total value |
11 u |
8 u + 56 |
(a)
Number of chairs in the extra 7 rows
= 7 x 8
= 56
(b)
Total number of chairs in the first arrangement
= 1 u x 11
= 11 u
Total number of chairs in the second arrangement
= 8(1 u + 7)
= 8 u + 56
If 29 chairs were included in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
11 u + 29 = 8 u + 56
11 u - 8 u = 56 - 29
3 u = 27
1 u = 27 ÷ 3 = 9
Number of chairs in the school hall in the end
= 9 x 11 + 29
= 99 + 29
= 128
Answer(s): (a) 56; (b) 128
