Some adults board a school bus.
At Bus Stop A,
29 of them alight
and 11 adults board.
At Bus Stop B,
58 of the adults alight
and 3 board.
If there are 15 adults on the bus now,
how many adults are on the bus at first?
|
Number of adults |
Before |
9 u |
|
Change 1 At Bus Stop A |
- 2 u + 11 |
|
After 1 |
7 u + 11 |
8 p |
Change 2 At Bus Stop B |
|
- 5 p + 3 |
After 2 |
|
15 |
Working backwards.
Number of adults in the end = 15
8 p - 5 p = 15 - 3
3 p = 12
1 p = 12 ÷ 3 = 4
8 p = 8 x 4
8 p = 32
7 u + 11 = 8 p
7 u + 11 = 32
7 u = 32 - 11
7 u = 21
1 u = 21 ÷ 7 = 3
Total number of adults at first
= 9 u
= 9 x 3
= 27
Answer(s): 27