if x=5, y=4; cout<< x++* y--; what will print?

Answer 1

it will print 20 but after printing the values will be
x=6 y=3

Answer 2

20 will be printed into the screen
final result is a bit general since the code could continue after that cout command (u might continue using y and x - maybe its a loop for example)

Answer 3

so, final result 20?