Two roommates plan to spend their evening with a marathon of Saw horror movies. Because it is a marathon, they must start with the first movie in the series and continue in order. Their willingness to pay for the rental of each movie is as follows:If each movie rental costs $6, how many movies should they rent? 

• A. One movie
• B. Two movie
• C. Three movies
• D. Four movies

Answer: (C)

Verified step by step guidance

1. Identify the willingness to pay for each movie by both roommates from the table. Ricky's willingness to pay is $9, $7, $5, and $3 for Saw I, II, III, and IV respectively. Martin's willingness to pay is $7, $5, $3, and $1 for Saw I, II, III, and IV respectively.
2. Calculate the total willingness to pay for each movie by adding Ricky's and Martin's willingness to pay. For Saw I, it is $9 + $7 = $16. For Saw II, it is $7 + $5 = $12. For Saw III, it is $5 + $3 = $8. For Saw IV, it is $3 + $1 = $4.
3. Compare the total willingness to pay for each movie with the cost of renting a movie, which is $6. Determine how many movies they should rent by checking if the total willingness to pay is greater than or equal to the cost.
4. For Saw I, the total willingness to pay is $16, which is greater than $6, so they should rent it. For Saw II, the total willingness to pay is $12, which is also greater than $6, so they should rent it. For Saw III, the total willingness to pay is $8, which is greater than $6, so they should rent it.
5. For Saw IV, the total willingness to pay is $4, which is less than $6, so they should not rent it. Therefore, they should rent three movies: Saw I, Saw II, and Saw III.