Some pupils board a school bus.
At Bus Stop A,
29 of them alight
and 12 pupils board.
At Bus Stop B,
58 of the pupils alight
and 2 board.
If there are 17 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 |
- 2 u + 12 |
|
After 1 |
7 u + 12 |
8 p |
Change 2 At Bus Stop B |
|
- 5 p + 2 |
After 2 |
|
17 |
Working backwards.
Number of pupils in the end = 17
8 p - 5 p = 17 - 2
3 p = 15
1 p = 15 ÷ 3 = 5
8 p = 8 x 5
8 p = 40
7 u + 12 = 8 p
7 u + 12 = 40
7 u = 40 - 12
7 u = 28
1 u = 28 ÷ 7 = 4
Total number of pupils at first
= 9 u
= 9 x 4
= 36
Answer(s): 36