(a) Write a procedure (count-even n) that counts the number of even digits in the decimal representation of the number n. For example, (count-even 234) should return 2.
(b) Write a procedure (postage wt) that computes the amount of postage to be included on a letter given its weight, wt. Use the following rules:
Less than 30 grams, 15 cents
30 to 49 grams, 17 cents
50 to 99 grams, 22 cents
100 and over grams, 1 cent for each 4 grams.
(c) The specification for (b) has a problem of ambiguity. What is it and what does your procedure do regarding the problem?