Set 4 : Fast Food Joint

Q1-4. Healthy Bites is a fast food joint serving three items: burgers, fries and ice cream. It has two employees Anish and Bani who prepare the items ordered by the clients. Preparation time is 10 minutes for a burger and 2 minutes for an order of ice cream. An employee can prepare only one of these items at a time. The fries are prepared in an automatic fryer which can prepare up to 3 portions of fries at a time, and take 5 minutes irrespective of the number of portions. The fryer does not need an employee to constantly attend to it, and we can ignore time taken by an employee to start and stop the fryer; thus, an employee can be engaged in preparing other items while the frying is on. However, fries cannot be prepared in anticipation of future orders.
Healthy Bites wishes to serve the orders as early as possible. The individual items in any orders are served as and when ready; however, the order is considered to be completely served only when all the items of that order are served.
The table below gives the orders of three clients and the times at which they placed their orders:

1. Assume that only one client’s order can be processed at any given point of time. So, Anish or Bani cannot start preparing a new order while previous order is being prepared.
At what time is the order placed by client 1 completely served?

1. 10:17
2. 10:10
3. 10:15
4. 10:20

EXPLANATION

Answer: 10:10

Assume that only one client’s order can be processed at any given point of time. So, Anish or Bani cannot start preparing a new order while previous order is being prepared.
Order can get delivered by 10:10.
Hence, the answer is “10:10”.

Choice B is the correct answer.

2. Assume that only one client’s order can be processed at any given point of time. So, Anish or Bani cannot start preparing a new order while previous order is being prepared.
At what time is the order placed by client 3 completely served?

1. 10:35
2. 10:22
3. 10:25
4. 10:17

EXPLANATION

Client 1 can get his/her order delivered by 10:10.



Client 2: Order of 2 fries and one ice cream



Can get completed by 10:15. Client 3 should start by 10:15

Client 3: 1 burger and 1 fries



Order can get delivered by 10:25.
Hence, the answer is “10:25”.

Choice C is the correct answer.

3. Suppose the employees are allowed to process multiple orders at a time, but the preference would be to finish orders of clients who placed their orders earlier.
At what time is the order placed by client 2 completely served?

1. 10:10
2. 10:12
3. 10:15
4. 10:17

EXPLANATION

Client 1: 1 burger, 3 portions of fries, 1 order of ice cream

Can get completed by 10:10. But Bani is free by 10:02 as the fries can run on Autopilot
Client 2: Order of 2 fries and one ice cream

This can also get get completed by 10:10. Bani can keep second set of fries and handle ice-cream also.
Hence, the answer is “10:10”.

Choice B is the correct answer.

4. Suppose the employees are allowed to process multiple orders at a time, but the preference would be to finish orders of clients who placed their orders earlier.
Also assume that the fourth client came in only at 10:35. Between 10:00 and 10:30, for how many minutes is exactly one of the employees idle?

1. 7
2. 10
3. 15
4. 23

EXPLANATION

Client 1: 1 burger, 3 portions of fries, 1 order of ice cream



Anish is busy till 10:10. Bani is busy till 10:02. Next order comes in at 10:05. Bani is idle from 10:02 to 10:05. He is idle for 3 min.

Client 2: 2 fries and 1 ice-cream: Order comes at 10:05



Bani starts preparing 1 ice-cream for client 2 from 10:05, he also keeps the fries on the fryer at 10:05.

Client 3: 1 Burger and 1 ice-cream: Order comes at 10:07



Anish finishes 1 Burger for client 1 at 10:10. Anish is idle from 10:10 to 10:17 when Bani is busy with Burger. After that, both will be idle. Anish is idle for 7 min from 10:10 to 10:17 and Bani is idle for 3 min from 10:02 to 10:05.
So, exactly one employee will be idle for 7 + 3 = 10 min.
Hence, the answer is “10”.

Choice B is the correct answer.