Question

what does the teacher mean for ps2 question 3, the largest number? can't it go on forever?

Answer 1

nope, it doesn't go on for ever, at some point all numbers above n can be bought. n is the largest number that cannot be bought - write a program to find n. assume the theorem presented prior to question 2 is correct - did you figure out why the theorem is correct?

Answer 2

well I think it can go on forever in a general case, that's why we need a limit for the loop (for n in range(1, 200) ), in the example of the McNuggets (6, 9, 20) as there's 6 successive numbers that can be bought, according to the theorem there must be a largest number that can't be bought.

Answer 3

It can't go on forever. It will probably help to make a list on paper. Basically, once reach a certain point in the "tens" column i(1, 2, 3, 4, 5 for 10, 20, 30, 40, 50, respectively), you have all 10 digits in the "ones" column (0-9).