In the school hall, chairs were arranged in rows of 14. During a function, 34 chairs were added to accommodate the number of people. The chairs were rearranged to form rows of 10. As a result, there were 7 more rows.
- How many chairs were there in the extra 7 rows?
- How many chairs were there in the school hall in the end?
|
First arrangement |
Second arrangement |
Number |
1 u |
1 u + 7 |
Value |
14 |
10 |
Total value |
14 u |
10 u + 70 |
(a)
Number of chairs in the extra 7 rows
= 7 x 10
= 70
(b)
Total number of chairs in the first arrangement
= 1 u x 14
= 14 u
Total number of chairs in the second arrangement
= 10(1 u + 7)
= 10 u + 70
If 34 chairs were included in the first arrangement, the total number of chairs in the first arrangement and the second arrangement will be the same.
14 u + 34 = 10 u + 70
14 u - 10 u = 70 - 34
4 u = 36
1 u = 36 ÷ 4 = 9
Number of chairs in the school hall in the end
= 9 x 14 + 34
= 126 + 34
= 160
Answer(s): (a) 70; (b) 160