Some passengers board a school bus.
At Bus Stop A,
35 of them alight
and 7 passengers board.
At Bus Stop B,
47 of the passengers alight
and 4 board.
If there are 13 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 |
- 3 u + 7 |
|
After 1 |
2 u + 7 |
7 p |
Change 2 At Bus Stop B |
|
- 4 p + 4 |
After 2 |
|
13 |
Working backwards.
Number of passengers in the end = 13
7 p - 4 p = 13 - 4
3 p = 9
1 p = 9 ÷ 3 = 3
7 p = 7 x 3
7 p = 21
2 u + 7 = 7 p
2 u + 7 = 21
2 u = 21 - 7
2 u = 14
1 u = 14 ÷ 2 = 7
Total number of passengers at first
= 5 u
= 5 x 7
= 35
Answer(s): 35