There were
13 as many children as adults on a bus. At the first bus stop, 7 children and 7 adults boarded the bus. There were then
45 as many children as adults. How many children were on the bus at first?
| |
Children |
Adults |
Difference |
| Before |
1x1 =
1 u |
3x1 =
3 u |
2x1 =
2 u |
| Change |
+ 7 |
+ 7 |
|
| After |
4x2 =
8 u |
5x2 =
10 u |
1x2 =
2 u |
Since equal number of children and adults boarded the bus, the difference in the number of children and adults at first and in the end remains the same. LCM of 2 and 1 is 2.
Number of children who boarded the bus
= 8 u - 1 u
= 7 u
7 u = 7
1 u = 7 ÷ 7 = 1
Number of children at first
= 1 u
= 1 x 1
= 1
Answer(s): 1
