PSLEThere were a total of 129 tables and chairs in a parade square. There were 2 times as many chairs as tables. After 30 chairs and some tables were thrown away, there were 4 times as many chairs as tables left. How many tables were thrown away from the parade square?
|
Tables |
Chairs |
Total |
Before |
1 u |
2 u |
129 |
Change |
- ? |
- 30 |
|
After |
1 p |
4 p |
|
Number of tables and chairs at first
= 2 u + 1 u
= 129
3 u = 129
1 u = 129 ÷ 3 = 43
Number of chairs at first
= 2 u
= 2 x 43
= 86
Number of chairs left
= 86 - 30
= 56
4 p = 56
1 p = 56 ÷ 4 = 14
Number of tables thrown away from the parade square
= 43 - 14
= 29
Answer(s): 29