A 1-week pass to all places of interest for one person costs $260. The management gives a concession to a group of 39 tourists. For every 3 tourists who purchase the 1-week pass, the 4th tourist gets free access to the places of interest. How much does each tourist pay in this arrangement if they share the total cost equally?
For every 3 tourists, 4th tourist gets free access.

Number of tourists in eact set
= 3 + 1
= 4

Number of sets of 4 tourists
= 39 ÷ 4
= 9 r 3 

There are 9 sets of 4 tourists in 39 tourists, so 9 tourists will get free access.

Number of tickets to be paid for
= 39 - 9
= 30

Total cost of tickets
= 30 x 260
= $7800

Cost for each tourist
= 7800 ÷ 39
= $200
 
Answer(s): $200