PSLEThere were a total of 156 tables and benches in a school field. There were 3 times as many benches as tables. After 17 benches and some tables were removed, there were 5 times as many benches as tables left. How many tables were removed from the school field?
|
Tables |
Benches |
Total |
Before |
1 u |
3 u |
156 |
Change |
- ? |
- 17 |
|
After |
1 p |
5 p |
|
Total number of tables and benches
= 3 u + 1 u
= 4 u
4 u = 156
1 u = 156 ÷ 4 = 39
Number of benches at first
= 3 u
= 3 x 39
= 117
Number of benches left
= 117 - 17
= 100
5 p = 100
1 p = 100 ÷ 5 = 20
Number of tables removed from the school field
= 39 - 20
= 19
Answer(s): 19