A ferry can carry a maximum of 20 adults or 45 children. A ticket for an adult cost $40 and a ticket for a child cost $35. A group of adults and children took 4 such ferries at maximum load on a ferry trip. The total amount paid for the children was $825 less than the total amount paid for the adults.
- How many adults were there?
- How many children were there?
Number of adults |
Amount paid for adults |
Number of children |
Amount paid for children |
Difference in total amounts paid |
80 |
80 x 40 = 3200 |
0 |
0 x 35 = 0 |
3200 - 0 = 3200 |
- 4 |
|
+ 9 |
|
- 475 |
76 |
76 x 40 = 3040 |
9 |
9 x 35 = 315 |
3040 - 315 = 2725 |
60 |
|
45 |
|
825 |
20 adults → 45 children
(÷5)4 adults → 9 children
From every decrease of 4 adults, there is an increase of 9 children and the difference in the total amounts paid between the adults and the children will be reduced by $475.
If all 4 ferries are occupied by only adults, total number of adults
= 4 x 20
= 80
Total difference
= 3200 - 825
= $2375
Small difference
= 3200 - 2725
= $475
Number of sets
= 2375 ÷ 475
= 5
Total decrease in the number of adults
= 5 x 4
= 20
(a)
Number of adults
= 80 - 20
= 60
(b)
Number of children
= 5 x 9
= 45
Answer(s): (a) 60; (b) 45