Some children board a school bus.
At Bus Stop A,
16 of them alight
and 10 children board.
At Bus Stop B,
14 of the children alight
and 3 board.
If there are 18 children on the bus now,
how many children are on the bus at first?
|
Number of children |
Before |
6 u |
|
Change 1 At Bus Stop A |
- 1 u + 10 |
|
After 1 |
5 u + 10 |
4 p |
Change 2 At Bus Stop B |
|
- 1 p + 3 |
After 2 |
|
18 |
Working backwards.
Number of children in the end = 18
4 p - 1 p = 18 - 3
3 p = 15
1 p = 15 ÷ 3 = 5
4 p = 4 x 5
4 p = 20
5 u + 10 = 4 p
5 u + 10 = 20
5 u = 20 - 10
5 u = 10
1 u = 10 ÷ 5 = 2
Total number of children at first
= 6 u
= 6 x 2
= 12
Answer(s): 12