# Screen Time Puzzle

Find the time of screening of each of the movies in each of the screens. Need help to solve this.Please share Approach.

Source : IMS

• Sorry if I missed this, what exactly are we trying to solve? Oct 15, 2018 at 14:35
• @RobertS. I am currently thinking we have to figure out when the movies were screened on all 3 screens Oct 15, 2018 at 14:37

Screen 1:

10 AM : A
12:30 PM : A
3 PM : A
5:30 PM : B
7:30 PM : C
10:30 PM : D

Screen 2:

10 AM : D
12:30 PM : B
2:30 PM : B
4:30 PM : D
7 PM : C

Screen 3:

10 AM : C
1 PM : A
3:30 PM : D
6 PM : B
8 PM : C
11 PM : D

Method for solving:

Started by solving for what movies were played on screen 3 with the info on the 2nd table. For example, since there are 4 screening of movie A and 3 of them are being screened on screen 1 and none on screen 2 there is one screening on screen 3. Using similar logic for the rest I deduced that there was 1 screening of A, 1 of B, 2 of C, and 2 of D on screen 3.

Next I started by figuring out the times possible, which lead to my solving of screen 1. Since 3 screening must happen of A on screen 1 only one slot would not be possible. If you look at the lengths of the films you can tell that you cannot have both the 12:30 PM and 1 PM slot happen at the same screen becuase movie A is too long. This means that the 10 AM slot and the 3PM slot of A were guaranteed to be in screen 1. After that I basically went through A and found the time slots that would be possible for each movie based on their lengths and and which movies needed to be screened in screen 1.
After screen 1 was solved I tried to work out the rest starting with screen 3 (because I had figured out that movie A had to be screened there at 1 PM). Similarly to how I solved for A, I tried to optimize times by looking at the ending and starting times for movies and fit them all best I could which lead to my answer for screen 3 and screen 2 (since it just filled in the leftovers).

• This is close, but Screen 2 has too large a gap between 12:30 and 3:30 for movie B, and Screen 3 has too short a gap between 1:00 and 2:30. Switching these around should fix the answer. Oct 16, 2018 at 0:50
• Your answer is partially correct. There is an error in screen 1 12:30 pm and 1:00 pm cant be together for movie A. Thanks for your approach. It was helpful. @gabbo1092.
– sam
Oct 16, 2018 at 2:46
• @Yessoan Thanks somehow I had misinterpreted the rules as a minimum of 15 min difference not a set minimum. Had to do some adjusting but should all be fixed now. Oct 16, 2018 at 12:22

A is shown in theaters

1, 1, 3, then 1
This can be deduced directly from the tables.

B is shown in theaters

2, 2, 1, then 3
Theater 1 is occupied by A from 10-5:30, so the only B slot that fits is 5:30.

C is shown in theaters

3, 2, 1, then 3
C is across all three theaters at 7-8, so must start in theater 3.

D is shown in theaters

2, 3, 2, 1, then 3.
Must start in theater two, fill in the rest of the gaps.