Answer:
There are 8 adults in the group.
Step-by-step explanation:
Let the number of adults in the group be 'x'.
Given:
Number of children = 1
Number of adults = 'x'
Cost for a ticket of adult = $9
Cost for a ticket of a child = $6
Total cost = $78
Total cost is equal to total cost of tickets of 'x' adults plus cost of ticket of 1 child.
Unit cost of 1 adult × Number of adults + cost of ticket of 1 child = Total cost
Framing in equation form, we get:
<u><em>Adding -6 on both sides, we get:</em></u>
<u><em>Dividing both sides by 9, we get:</em></u>
Therefore, there are 8 adults in the group.