PSLEThere were a total of 180 tables and chairs in a basketball court. There were 3 times as many chairs as tables. After 30 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 basketball court?
|
Tables |
Chairs |
Total |
Before |
1 u |
3 u |
180 |
Change |
- ? |
- 30 |
|
After |
1 p |
5 p |
|
Number of tables and chairs at first
= 3 u + 1 u
= 180
4 u = 180
1 u = 180 ÷ 4 = 45
Number of chairs at first
= 3 u
= 3 x 45
= 135
Number of chairs left
= 135 - 30
= 105
5 p = 105
1 p = 105 ÷ 5 = 21
Number of tables thrown away from the basketball court
= 45 - 21
= 24
Answer(s): 24