Answer:
5407
Step-by-step explanation:
We are given that A company has a total of 6,500 computers, and 1 week ago, one of those computers was infected with a virus.
In each of the next 7 days, the number of computers newly infected with the virus that day has been 3 times what it was the previous day.
Initially no. of computers infected with virus = 1
Since we are given that every day the no. of infected computers will be 3 times the no. of infected computers on previous day
So, no. of infected computers on 2nd day = 3
No. of infected computers on 3rd day = 383 = 9
So, the sequence becomes: 1,3,9 ,.....
Since G.P. is formed
So, common ratio r = \(\frac{3}{1} =\frac{9}{3}=3\)
Sum of n terms in G.P. = \(S_n=\frac{a(1-r^n)}{1-r}\)
Where a is the initial term
n = no. of terms
r = common ratio
Now no. of infected computers after 7 days will be :
\(S_7=\frac{1(1-3^n)}{1-3}\)
\(S_7=1093\)
Thus the no. of infected computers are 1093
So, no. of infected computers = Total computers - infected computers
=6500-1093
=5407
Hence the no.of office's computers are not infected with the virus is 5407
