Some children board a school bus.
At Bus Stop A,
13 of them alight
and 12 children board.
At Bus Stop B,
59 of the children alight
and 10 board.
If there are 18 children on the bus now,
how many children are on the bus at first?
|
Number of children |
Before |
3 u |
|
Change 1 At Bus Stop A |
- 1 u + 12 |
|
After 1 |
2 u + 12 |
9 p |
Change 2 At Bus Stop B |
|
- 5 p + 10 |
After 2 |
|
18 |
Working backwards.
Number of children in the end = 18
9 p - 5 p = 18 - 10
4 p = 8
1 p = 8 ÷ 4 = 2
9 p = 9 x 2
9 p = 18
2 u + 12 = 9 p
2 u + 12 = 18
2 u = 18 - 12
2 u = 6
1 u = 6 ÷ 2 = 3
Total number of children at first
= 3 u
= 3 x 3
= 9
Answer(s): 9