In the school hall, chairs were arranged in rows of 16. During a function, 17 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 11. 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 |
16 |
11 |
Total value |
16 u |
11 u + 77 |
(a)
Number of chairs in the extra 7 rows
= 7 x 11
= 77
(b)
Total number of chairs in the first arrangement
= 1 u x 16
= 16 u
Total number of chairs in the second arrangement
= 11(1 u + 7)
= 11 u + 77
If 17 chairs were included in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
16 u + 17 = 11 u + 77
16 u - 11 u = 77 - 17
5 u = 60
1 u = 60 ÷ 5 = 12
Number of chairs in the school hall in the end
= 12 x 16 + 17
= 192 + 17
= 209
Answer(s): (a) 77; (b) 209