Some adults board a school bus.
At Bus Stop A,
47 of them alight
and 12 adults board.
At Bus Stop B,
38 of the adults alight
and 2 board.
If there are 17 adults on the bus now,
how many adults are on the bus at first?
|
Number of adults |
Before |
7 u |
|
Change 1 At Bus Stop A |
- 4 u + 12 |
|
After 1 |
3 u + 12 |
8 p |
Change 2 At Bus Stop B |
|
- 3 p + 2 |
After 2 |
|
17 |
Working backwards.
Number of adults in the end = 17
8 p - 3 p = 17 - 2
5 p = 15
1 p = 15 ÷ 5 = 3
8 p = 8 x 3
8 p = 24
3 u + 12 = 8 p
3 u + 12 = 24
3 u = 24 - 12
3 u = 12
1 u = 12 ÷ 3 = 4
Total number of adults at first
= 7 u
= 7 x 4
= 28
Answer(s): 28