Two.
END is a statement. It tells the system to end this run of the program.
Look at the program:
PRINT 10 + 5 END
If you run this program, the computer starts with the first statement:
PRINT 10 + 5
That statement says to:
10,
+,
5,
and
=.
The calculator then shows 15.
In QBasic there are many things that can be done with the sum. To see the sum on the monitor, use PRINT.