## BCA 4th semester long question solution 2078

**9. What is CPU Scheduling? Write does the criteria for CPU scheduling? Consider the following set of processes, with the length of the CPU burst given in millisecond , draw Gant chart illustrating their execution and calculate average waiting time using:**

a) First come First serve

b) Shortest Job first

c) None-preemptive priority (smaller number implies higher priority)

d) Round robin (quantum=1)

Process | Burst Time | Priority |

P_{0} | 10 | 3 |

P_{1} | 1 | 1 |

P_{2} | 2 | 5 |

P_{3} | 1 | 4 |

P_{4} | 5 | 2 |

## BCA 4th semester long question solution 2078

a) First Come First Serve

Solution

Process | Arrival Time (AT) | Burst Time (BT) | Completion time (CT) | Turned around Time (TAT) | Waiting Time (WT) |

P_{0} | 0 | 10 | 10 | 10 | 0 |

P_{1} | 0 | 1 | 11 | 11 | 10 |

P_{2} | 0 | 2 | 13 | 13 | 11 |

P_{3} | 0 | 1 | 14 | 14 | 13 |

P_{4} | 0 | 5 | 19 | 19 Total=67 | 14 Total= 48 |

Note:- CT=From Gantt chart

TAT= CT-AT

WT=TAT-BT

P_{0}=This process come first so we start at first AT=0 here in BT= 10

P_{1}= P_{0} को BT लाई P_{1}मा जोडनु पार्ने हुन्छ । Eg, [ P_{0} Burst time (BT)=10+P_{1}(1)=11]

Gantt chart

P_{0} | P_{1} | P_{2} | P_{3} | P_{4} |

Total Waiting Time= 0+10+11+13+14

=48

Average waiting time=Total waiting time/ process

48/6

=9.6

Total turn around Time= 10+11+13+14+19

=67

Average turn around time= Total turn around time/ Process

= 67/5

= 13.4

b) Short job first

Solution

Process | Burst Time (BT) | Priority | Completion time (CT) | Turned around Time (TAT) | Waiting Time (WT) |

P_{0} | 10 | 3 | 10 | 10 | 0 |

P_{1} | 1 | 1 | 11 | 11 | 10 |

P_{2} | 2 | 5 | 14 | 14 | 12 |

P_{3} | 1 | 4 | 12 | 12 | 11 |

P_{4} | 5 | 2 | 15 | 15 Total=62 | 10 Total= 43 |

**Gantt chart**

P_{0} | P_{1} | P_{2} | P_{3} | P_{4} |

Total waiting Time=0+10+12+11+10

=43

Average waiting time= Total waiting time/process

=43/5

=8.6

Total turnaround time= 10+11+14+12+15

=62

Average turn around time= total trunaround time/Process

=62/5

=12.4

C) Non-preemptive priority (small number implies higher)

Process | Burst Time (BT) | Priority | Completion time (CT) | Turned around Time (TAT) | Waiting Time (WT) |

P_{0} | 10 | 3 | 10 | 10 | 0 |

P_{1} | 1 | 1 | 11 | 11 | 10 |

P_{2} | 2 | 5 | 19 | 19 | 17 |

P_{3} | 1 | 4 | 17 | 17 | 16 |

P_{4} | 5 | 2 | 16 | 16 Total=73 | 11 Total= 54 |

**Gantt chart**

P_{0} | P_{1} | P_{2} | P_{3} | P_{4} |

Total waiting Time=0+10+17+16+11

=54

Average waiting time= Total waiting time/process

=54/5

=10.8

Total turnaround time= 10+11+19+17+16

=73

Total turn around time= total trunaround time/Process

=73/5

=14.6

d) Round Robin (quantum = 1)

Process | Burst Time (BT) | Completion time (CT) | Turned around Time (TAT) | Waiting Time (WT) |

P_{0} | 10 | 10 | 10 | 0 |

P_{1} | 1 | 11 | 11 | 10 |

P_{2} | 2 | 15 | 15 | 13 |

P_{3} | 1 | 13 | 13 | 12 |

P_{4} | 5 | 19 | 19 Total=68 | 15 Total= 50 |

**Gantt chart**

P_{0} | P_{1} | P_{2} | P_{3} | P_{4} | P_{2} | P_{4} |

Total waiting Time=0+10+13+12+15

=50

Average waiting time= Total waiting time/process

=50/5

=10

Total turnaround time= 10+11+15+13+19

=68

Total turn around time= total trunaround time/Process

=68/5

=13.6

## BCA 4th semester long question solution 2078

**Bachelor in computer Applications ** Full Marks:60

Course Title: **Numerical Method ** Pass Marks: 24

Code No: **CACS252** Time: 3 hours

Semester: IV

**Group A**

i. Which of the following is numerical error

a. Missing Information

b. Data Error

**c. Roundup Error**

d. Conversion Error

ii. Which of the following method is used solve the system of linear equation?

a. Bisection Method

b. False Position Method

c. Taylor series Method

**d.** **Matrix Inverse Method**

iii. How many significant digits in the number 105.78904560?

**a. 11**

b. 3

c. 8

d. 10

iv. What will be the solution of equations x+y=3 and 2x+2y=6?

a. Unique solution

**b. Infinite Solution **

c. No Solution

d. III-condition

v. Which of the following formula is four-point formula to estimate integration?

a. Trapezoidal Rule

b. Simpson’s 1/3 Rule

**c. Simpson’s 3/8 Rule**

d. Boole’s Rule

vi. When a differential equation is considered as an ordinary differential equation?

**a. If it has one independent variable**

b. if it has one dependent variable

c. more than one dependent variable

d. more than one independent variables