(i) n = x + y / x;
= 5 + 4/5
= 5 + 0
= 5 (both x and y are int type. Therefore only integer part of quotient is considered)
(ii) z = m * x + y;
= 2.5*5 + 4 (m is float type, so x value is promoted to float [implicit conversion])
= 12.5 + 4
= 16 (2 is int type. So '2', the fractional part is discarded)
(iii) z *= x * m + x;
= 5*2.5+x
= 12.5 +5
= 18 (z is int type, therefore the fractional part is removed. x is incremented after the addition)

(i) 15.223 = 0.15223E2
(ii) 211.05 = 0.21105E3
(iii) 0.00025 = 0.25E-3

(i) The program is broken down into modules, thus making it more simplified.
(ii) More library functions can be used, at the same time size of the program is retained.

C++ program is a collection of functions. Every C++ program must have a main function. The main() function is the starting point where all C++ programs begin their execution. Therefore, the executable statements should be inside the main() function.

Header files contain definitions of Functions and Variables, which is imported or used into any C++ program by using the pre-processor #include statement. Header files have an extension ".h" which contains C++ function declaration and macro definition.
Example: #include<iostream.h>