Some students board a school bus.
At Bus Stop A,
15 of them alight
and 7 students board.
At Bus Stop B,
57 of the students alight
and 6 board.
If there are 16 students on the bus now,
how many students are on the bus at first?
|
Number of students |
Before |
5 u |
|
Change 1 At Bus Stop A |
- 1 u + 7 |
|
After 1 |
4 u + 7 |
7 p |
Change 2 At Bus Stop B |
|
- 5 p + 6 |
After 2 |
|
16 |
Working backwards.
Number of students in the end = 16
7 p - 5 p = 16 - 6
2 p = 10
1 p = 10 ÷ 2 = 5
7 p = 7 x 5
7 p = 35
4 u + 7 = 7 p
4 u + 7 = 35
4 u = 35 - 7
4 u = 28
1 u = 28 ÷ 4 = 7
Total number of students at first
= 5 u
= 5 x 7
= 35
Answer(s): 35