In the school hall, chairs were arranged in rows of 11. During a function, 19 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 8. As a result, there were 8 more rows.
- How many chairs were there in the extra 8 rows?
- How many chairs were there in the school hall in the end?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 8 |
Value |
11 |
8 |
Total value |
11 u |
8 u + 64 |
(a)
Number of chairs in the extra 8 rows
= 8 x 8
= 64
(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 + 8)
= 8 u + 64
If 19 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 + 19 = 8 u + 64
11 u - 8 u = 64 - 19
3 u = 45
1 u = 45 ÷ 3 = 15
Number of chairs in the school hall in the end
= 15 x 11 + 19
= 165 + 19
= 184
Answer(s): (a) 64; (b) 184