Question

can someone answer this computer maths question, please give a detailed answer with explanation thanks!!

Q1. A computer virus is planted on 4 machines the first day. Every day each infected machine from the day before infects 7 new machines. By the end of the second day, a program was developed to counteract the virus and one machine was cleaned. Each day thereafter, eight times as many machines are clean as were clean the day before a. If an is the total number of infected computers on day n, find the recurrence relation for an b. Solve this recurrence relation, that is, find the closed form solution for an. 72- c. Use the solution to find out how many days it will take to clean all infected machines.

Answer 1

Machines infected Solo Hon wes daweloped and tested on a machine hinie 7. n-l に1

C) f(1) = 4

f(2) = 28 - 1 =27

f(3) = 7(27 - 8) = 133

f(4) = 7(133 - 64) = 69

f(5) = 7(69 - 512) , here 69 of the infected systems were cured as the target 512

Hence it took 5 days clean all infected machines.