Some adults board a school bus.
At Bus Stop A,
35 of them alight
and 4 adults board.
At Bus Stop B,
15 of the adults alight
and 10 board.
If there are 18 adults on the bus now,
how many adults are on the bus at first?
|
Number of adults |
Before |
5 u |
|
Change 1 At Bus Stop A |
- 3 u + 4 |
|
After 1 |
2 u + 4 |
5 p |
Change 2 At Bus Stop B |
|
- 1 p + 10 |
After 2 |
|
18 |
Working backwards.
Number of adults in the end = 18
5 p - 1 p = 18 - 10
4 p = 8
1 p = 8 ÷ 4 = 2
5 p = 5 x 2
5 p = 10
2 u + 4 = 5 p
2 u + 4 = 10
2 u = 10 - 4
2 u = 6
1 u = 6 ÷ 2 = 3
Total number of adults at first
= 5 u
= 5 x 3
= 15
Answer(s): 15