Answer:

' Program to convert pounds sterling to dollars.
' The program keeps running until the user hits CONTROL-BREAK.
DO
  PRINT "Enter price in pounds"
  INPUT PRICE
  PRINT "Price in dollars:", PRICE * 1.79
LOOP
END

To make a small program repeat itself endlessly, enclose it with DO ... LOOP. DO and LOOP are brackets that show the beginning and end of the repeating part of a program.

Changing Conversion Rate

Now, when the program is run, its output is:

Enter price in pounds
? 100
Price in dollars: 179
Enter price in pounds
? 50
Price in dollars: 89.5
Enter price in pounds
? 1
Price in dollars: 1.79
Enter price in pounds
?

(The INPUT statement waits for you to type something in, so the "?" prompt will stay there until you do.)

The conversion rate between pounds sterling and dollars changes every day. It would be nice if when you started the program at the beginning of the day that you could type in that day's conversion rate. Of course, you only want to do this once, when the program starts. Here is (nearly) what the new program looks like:

' Program to convert pounds sterling to dollars.
' First the user is asked for the number of dollars per pound.
' Then the program starts looping until the user hits CONTROL-BREAK.

PRINT ______________________________

INPUT _______

DO
  PRINT "Enter price in pounds"
  INPUT PRICE
  PRINT "Price in dollars:", PRICE * RATE
LOOP
END

Answer:

Changing Conversion Rate

QUESTION 21: