In the seminar room, chairs were arranged in rows of 15. During a workshop, 40 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 11. 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 seminar room in the end?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 8 |
Value |
15 |
11 |
Total value |
15 u |
11 u + 88 |
(a)
Number of chairs in the extra 8 rows
= 8 x 11
= 88
(b)
Total number of chairs in the first arrangement
= 1 u x 15
= 15 u
Total number of chairs in the second arrangement
= 11(1 u + 8)
= 11 u + 88
If 40 chairs were included in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
15 u + 40 = 11 u + 88
15 u - 11 u = 88 - 40
4 u = 48
1 u = 48 ÷ 4 = 12
Number of chairs in the seminar room in the end
= 12 x 15 + 40
= 180 + 40
= 220
Answer(s): (a) 88; (b) 220