Some passengers board a school bus.
At Bus Stop A,
710 of them alight
and 2 passengers board.
At Bus Stop B,
27 of the passengers alight
and 7 board.
If there are 17 passengers on the bus now,
how many passengers are on the bus at first?
|
Number of passengers |
Before |
10 u |
|
Change 1 At Bus Stop A |
- 7 u + 2 |
|
After 1 |
3 u + 2 |
7 p |
Change 2 At Bus Stop B |
|
- 2 p + 7 |
After 2 |
|
17 |
Working backwards.
Number of passengers in the end = 17
7 p - 2 p = 17 - 7
5 p = 10
1 p = 10 ÷ 5 = 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 passengers at first
= 10 u
= 10 x 4
= 40
Answer(s): 40