Some pupils board a school bus.
At Bus Stop A,
19 of them alight
and 2 pupils board.
At Bus Stop B,
57 of the pupils alight
and 2 board.
If there are 14 pupils on the bus now,
how many pupils are on the bus at first?
|
Number of pupils |
Before |
9 u |
|
Change 1 At Bus Stop A |
- 1 u + 2 |
|
After 1 |
8 u + 2 |
7 p |
Change 2 At Bus Stop B |
|
- 5 p + 2 |
After 2 |
|
14 |
Working backwards.
Number of pupils in the end = 14
7 p - 5 p = 14 - 2
2 p = 12
1 p = 12 ÷ 2 = 6
7 p = 7 x 6
7 p = 42
8 u + 2 = 7 p
8 u + 2 = 42
8 u = 42 - 2
8 u = 40
1 u = 40 ÷ 8 = 5
Total number of pupils at first
= 9 u
= 9 x 5
= 45
Answer(s): 45