Some passengers board a school bus.
At Bus Stop A,
13 of them alight
and 3 passengers board.
At Bus Stop B,
25 of the passengers alight
and 4 board.
If there are 19 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 + 3 |
|
After 1 |
2 u + 3 |
5 p |
Change 2 At Bus Stop B |
|
- 2 p + 4 |
After 2 |
|
19 |
Working backwards.
Number of passengers in the end = 19
5 p - 2 p = 19 - 4
3 p = 15
1 p = 15 ÷ 3 = 5
5 p = 5 x 5
5 p = 25
2 u + 3 = 5 p
2 u + 3 = 25
2 u = 25 - 3
2 u = 22
1 u = 22 ÷ 2 = 11
Total number of passengers at first
= 3 u
= 3 x 11
= 33
Answer(s): 33