In the seminar room, chairs were arranged in rows of 15. During a workshop, 33 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 12. As a result, there were 6 more rows.
- How many chairs were there in the extra 6 rows?
- How many chairs were there in the seminar room in the end?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 6 |
Value |
15 |
12 |
Total value |
15 u |
12 u + 72 |
(a)
Number of chairs in the extra 6 rows
= 6 x 12
= 72
(b)
Total number of chairs in the first arrangement
= 1 u x 15
= 15 u
Total number of chairs in the second arrangement
= 12(1 u + 6)
= 12 u + 72
If 33 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 + 33 = 12 u + 72
15 u - 12 u = 72 - 33
3 u = 39
1 u = 39 ÷ 3 = 13
Number of chairs in the seminar room in the end
= 13 x 15 + 33
= 195 + 33
= 228
Answer(s): (a) 72; (b) 228