Answer:
The program written in Python is as follows:
<em>See Explanation section for line by line explanation</em>
for n in range(100,1000):
isum = 0
for d in range(1,n):
if n%d == 0:
isum += d
if isum == n * 2:
print(n)
Explanation:
The program only considers 3 digit numbers. hence the range of n is from 100 to 999
for n in range(100,1000):
This line initializes sum to 0
isum = 0
This line is an iteration that stands as the divisor
for d in range(1,n):
This line checks if a number, d can evenly divide n
if n%d == 0:
If yes, the sum is updated
isum += d
This line checks if the current number n is a double-perfect number
if isum == n * 2:
If yes, n is printed
print(n)
<em>When the program is run, the displayed output is 120 and 672</em>
Answer:
There are different phases of railroad expansion with the innovations in technology.
Explanation:
Few of the technological innovations are described below that leads in railroad expansion more rapid.
1. Centralized Traffic control (CTC) is introduced in 1960's that is used to control the traffic on railroads using different signal control.
2. In 1990's after computer technology involvement, railway ticket and reservation system is automate and being centralized. That makes the railroad expansion improve.
3. Bullet train technology has been introduced, that makes the railway trains more faster.
4. Electric trains has been introduced to use green energy and reduce the dependency on the fuel to make environment clean and green.
Answer:
I guessed D, taking it right now, sorry if it's wrong
Explanation:
Since no answer choices, have to deduce it is Private Networks
