In the school hall, chairs were arranged in rows of 17. During a function, 38 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 13. 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 school hall in the end?
| |
First
arrangement |
Second
arrangement |
| Number |
1 u |
1 u + 6 |
| Value |
17 |
13 |
| Total value |
17 u |
13 u + 78 |
(a)
Number of chairs in the extra 6 rows
= 6 x 13
= 78
(b)
Total number of chairs in the first arrangement
= 1 u x 17
= 17 u
Total number of chairs in the second arrangement
= 13(1 u + 6)
= 13 u + 78
If 38 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 + 38 = 13 u + 78
17 u - 13 u = 78 - 38
4 u = 40
1 u = 40 ÷ 4 = 10
Number of chairs in the school hall in the end
= 10 x 17 + 38
= 170 + 38
= 208
Answer(s): (a) 78; (b) 208
