Some adults board a school bus.
At Bus Stop A,
16 of them alight
and 2 adults board.
At Bus Stop B,
14 of the adults alight
and 7 board.
If there are 16 adults on the bus now,
how many adults are on the bus at first?
|
Number of adults |
Before |
6 u |
|
Change 1 At Bus Stop A |
- 1 u + 2 |
|
After 1 |
5 u + 2 |
4 p |
Change 2 At Bus Stop B |
|
- 1 p + 7 |
After 2 |
|
16 |
Working backwards.
Number of adults in the end = 16
4 p - 1 p = 16 - 7
3 p = 9
1 p = 9 ÷ 3 = 3
4 p = 4 x 3
4 p = 12
5 u + 2 = 4 p
5 u + 2 = 12
5 u = 12 - 2
5 u = 10
1 u = 10 ÷ 5 = 2
Total number of adults at first
= 6 u
= 6 x 2
= 12
Answer(s): 12