; it will print out "76"
; do means an action will happen and then it will check if the while ;statement is true, if so again it will go to do or else it will exit from ;do while loop
I = I + 25; // it will add 25 to I
while ( I > 50 ); // then it will check if I is more than 50, if so it will again add 25 to I
it will print I out.
Practice problems mean you type them into your compiler, compile them, and see how they work. That's the best way to figure out how things work. For these, forget the internet -- pretend it doesn't exist. All you have is you, your computer, and your compiler.