In the seminar room, chairs were arranged in rows of 17. During a workshop, 27 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 15. As a result, there were 3 more rows.
- How many chairs were there in the extra 3 rows?
- How many chairs were there in the seminar room in the end?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 3 |
Value |
17 |
15 |
Total value |
17 u |
15 u + 45 |
(a)
Number of chairs in the extra 3 rows
= 3 x 15
= 45
(b)
Total number of chairs in the first arrangement
= 1 u x 17
= 17 u
Total number of chairs in the second arrangement
= 15(1 u + 3)
= 15 u + 45
If 27 chairs were included in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
17 u + 27 = 15 u + 45
17 u - 15 u = 45 - 27
2 u = 18
1 u = 18 ÷ 2 = 9
Number of chairs in the seminar room in the end
= 9 x 17 + 27
= 153 + 27
= 180
Answer(s): (a) 45; (b) 180