Some passengers board a school bus.
At Bus Stop A,
25 of them alight
and 9 passengers board.
At Bus Stop B,
37 of the passengers alight
and 8 board.
If there are 20 passengers on the bus now,
how many passengers are on the bus at first?
|
Number of passengers |
Before |
5 u |
|
Change 1 At Bus Stop A |
- 2 u + 9 |
|
After 1 |
3 u + 9 |
7 p |
Change 2 At Bus Stop B |
|
- 3 p + 8 |
After 2 |
|
20 |
Working backwards.
Number of passengers in the end = 20
7 p - 3 p = 20 - 8
4 p = 12
1 p = 12 ÷ 4 = 3
7 p = 7 x 3
7 p = 21
3 u + 9 = 7 p
3 u + 9 = 21
3 u = 21 - 9
3 u = 12
1 u = 12 ÷ 3 = 4
Total number of passengers at first
= 5 u
= 5 x 4
= 20
Answer(s): 20