PSLEThere were a total of 172 tables and chairs in a tuckshop. There were 3 times as many chairs as tables. After 17 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 tuckshop?
|
Tables |
Chairs |
Total |
Before |
1 u |
3 u |
172 |
Change |
- ? |
- 17 |
|
After |
1 p |
4 p |
|
Number of tables and chairs at first
= 3 u + 1 u
= 172
4 u = 172
1 u = 172 ÷ 4 = 43
Number of chairs at first
= 3 u
= 3 x 43
= 129
Number of chairs left
= 129 - 17
= 112
4 p = 112
1 p = 112 ÷ 4 = 28
Number of tables thrown away from the tuckshop
= 43 - 28
= 15
Answer(s): 15