In the school hall, chairs were arranged in rows of 12. During a function, 38 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 10. 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 |
12 |
10 |
Total value |
12 u |
10 u + 60 |
(a)
Number of chairs in the extra 6 rows
= 6 x 10
= 60
(b)
Total number of chairs in the first arrangement
= 1 u x 12
= 12 u
Total number of chairs in the second arrangement
= 10(1 u + 6)
= 10 u + 60
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.
12 u + 38 = 10 u + 60
12 u - 10 u = 60 - 38
2 u = 22
1 u = 22 ÷ 2 = 11
Number of chairs in the school hall in the end
= 11 x 12 + 38
= 132 + 38
= 170
Answer(s): (a) 60; (b) 170