Some students board a school bus.
At Bus Stop A,
47 of them alight
and 2 students board.
At Bus Stop B,
47 of the students alight
and 10 board.
If there are 16 students on the bus now,
how many students are on the bus at first?
|
Number of students |
Before |
7 u |
|
Change 1 At Bus Stop A |
- 4 u + 2 |
|
After 1 |
3 u + 2 |
7 p |
Change 2 At Bus Stop B |
|
- 4 p + 10 |
After 2 |
|
16 |
Working backwards.
Number of students in the end = 16
7 p - 4 p = 16 - 10
3 p = 6
1 p = 6 ÷ 3 = 2
7 p = 7 x 2
7 p = 14
3 u + 2 = 7 p
3 u + 2 = 14
3 u = 14 - 2
3 u = 12
1 u = 12 ÷ 3 = 4
Total number of students at first
= 7 u
= 7 x 4
= 28
Answer(s): 28