PSLEThere were a total of 162 tables and chairs in a canteen. There were 2 times as many chairs as tables. After 16 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 |
162 |
Change |
- ? |
- 16 |
|
After |
1 p |
4 p |
|
Number of tables and chairs at first
= 2 u + 1 u
= 162
3 u = 162
1 u = 162 ÷ 3 = 54
Number of chairs at first
= 2 u
= 2 x 54
= 108
Number of chairs left
= 108 - 16
= 92
4 p = 92
1 p = 92 ÷ 4 = 23
Number of tables thrown away from the canteen
= 54 - 23
= 31
Answer(s): 31