PSLEThere were a total of 108 tables and chairs in a parade square. There were 3 times as many chairs as tables. After 13 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 |
3 u |
108 |
Change |
- ? |
- 13 |
|
After |
1 p |
4 p |
|
Number of tables and chairs at first
= 3 u + 1 u
= 108
4 u = 108
1 u = 108 ÷ 4 = 27
Number of chairs at first
= 3 u
= 3 x 27
= 81
Number of chairs left
= 81 - 13
= 68
4 p = 68
1 p = 68 ÷ 4 = 17
Number of tables thrown away from the parade square
= 27 - 17
= 10
Answer(s): 10