Answer:

Explanation:
Given



Required
Determine the number of adults
First, we need to calculate the number of children

Given that:

Substitute 170 for Girls in


Convert to fraction

Cross Multiply

Divide both sides by 2



So, the number of children are:



Next, we calculate the number of people in the cinema.

Substitute 765 for Children

Make People the subject.



If 3/5 are children, then 2/5 are adults.
So:



