Some children board a school bus.
At Bus Stop A,
35 of them alight
and 6 children board.
At Bus Stop B,
14 of the children alight
and 4 board.
If there are 19 children on the bus now,
how many children are on the bus at first?
|
Number of children |
Before |
5 u |
|
Change 1 At Bus Stop A |
- 3 u + 6 |
|
After 1 |
2 u + 6 |
4 p |
Change 2 At Bus Stop B |
|
- 1 p + 4 |
After 2 |
|
19 |
Working backwards.
Number of children in the end = 19
4 p - 1 p = 19 - 4
3 p = 15
1 p = 15 ÷ 3 = 5
4 p = 4 x 5
4 p = 20
2 u + 6 = 4 p
2 u + 6 = 20
2 u = 20 - 6
2 u = 14
1 u = 14 ÷ 2 = 7
Total number of children at first
= 5 u
= 5 x 7
= 35
Answer(s): 35