At the school, Floor P and Floor Q had an equal number of desks at first. If 7 desks were removed from Floor Q and 7 times as many desks were removed from Floor P as Floor Q, the number of desks in Floor Q would be 3 times as many as in Floor P. Find the number of desks on each floor.
| |
Floor P |
Floor Q |
| Before |
1 u + 49 |
3 u + 7 |
| Change |
- 49 |
- 7 |
| After |
1 u |
3 u |
Number of desks removed from Floor P
= 7 x 7
= 49
Number of desks on Floor P and Floor Q at first is the same.
3 u + 7 = 1 u + 49
3 u - 1 u = 49 - 7
2 u = 42
1 u = 42 ÷ 2 = 21
Number of desks on each floor
= 1 u + 49
= 21 + 49
= 70
Answer(s): 70
