PSLEThere were a total of 102 tables and chairs in a hall. There were 2 times as many chairs as tables. After 13 chairs and some tables were thrown away, there were 5 times as many chairs as tables left. How many tables were thrown away from the hall?
|
Tables |
Chairs |
Total |
Before |
1 u |
2 u |
102 |
Change |
- ? |
- 13 |
|
After |
1 p |
5 p |
|
Number of tables and chairs at first
= 2 u + 1 u
= 102
3 u = 102
1 u = 102 ÷ 3 = 34
Number of chairs at first
= 2 u
= 2 x 34
= 68
Number of chairs left
= 68 - 13
= 55
5 p = 55
1 p = 55 ÷ 5 = 11
Number of tables thrown away from the hall
= 34 - 11
= 23
Answer(s): 23