perplexus.info :: Just Math : Consecutive Deletion

Consecutive Deletion (Posted on 2015-04-22)

N is a five-digit base ten positive integer formed entirely by nonzero digits.

Find the total number of values of N such that such that deleting consecutively the digit of the left, in each step, we obtain a divisor of the previous number.

See The Solution Submitted by K Sengupta

Rating: 5.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

computer solution

| Comment 1 of 8

For n = 11111 To 99999

ns = Str$(n)

If InStr(ns, "0") = 0 Then

prev = n

good = 1

For i = 1 To 4

ns = Mid(ns, 2)

newn = Val(ns)

If prev Mod newn <> 0 Then

good = 0: Exit For

End If

prev = newn

If good Then Text1.Text = Text1.Text & Str(n) & crlf: goodCt = goodCt + 1

End If

finds

53125

91125

95625

so there are 3 such values.

Posted by Charlie on 2015-04-22 14:20:58

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