Some passengers board a school bus.
At Bus Stop A,
13 of them alight
and 4 passengers board.
At Bus Stop B,
47 of the passengers alight
and 5 board.
If there are 17 passengers on the bus now,
how many passengers are on the bus at first?
|
Number of passengers |
Before |
3 u |
|
Change 1 At Bus Stop A |
- 1 u + 4 |
|
After 1 |
2 u + 4 |
7 p |
Change 2 At Bus Stop B |
|
- 4 p + 5 |
After 2 |
|
17 |
Working backwards.
Number of passengers in the end = 17
7 p - 4 p = 17 - 5
3 p = 12
1 p = 12 ÷ 3 = 4
7 p = 7 x 4
7 p = 28
2 u + 4 = 7 p
2 u + 4 = 28
2 u = 28 - 4
2 u = 24
1 u = 24 ÷ 2 = 12
Total number of passengers at first
= 3 u
= 3 x 12
= 36
Answer(s): 36