PSLEThere were a total of 177 tables and chairs in a canteen. There were 2 times as many chairs as tables. After 18 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 canteen?
|
Tables |
Chairs |
Total |
Before |
1 u |
2 u |
177 |
Change |
- ? |
- 18 |
|
After |
1 p |
4 p |
|
Number of tables and chairs at first
= 2 u + 1 u
= 177
3 u = 177
1 u = 177 ÷ 3 = 59
Number of chairs at first
= 2 u
= 2 x 59
= 118
Number of chairs left
= 118 - 18
= 100
4 p = 100
1 p = 100 ÷ 4 = 25
Number of tables thrown away from the canteen
= 59 - 25
= 34
Answer(s): 34