There were
34 as many children as adults on a bus. At the first bus stop, 3 children and 3 adults boarded the bus. There were then
79 as many children as adults. How many children were on the bus at first?
|
Children |
Adults |
Difference |
Before |
3x2 = 6 u |
4x2 = 8 u |
1x2 = 2 u |
Change |
+ 3 |
+ 3 |
|
After |
7x1 = 7 u |
9x1 = 9 u |
2x1 = 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 1 and 2 is 2.
Number of children who boarded the bus
= 7 u - 6 u
= 1 u
1 u = 3
1 u = 3 ÷ 1 = 3
Number of children at first
= 6 u
= 6 x 3
= 18
Answer(s): 18