MS Excel: Unique random number generator within a range

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I want to generate 10 groups out of numbers ranging from 1-60 (including both), with each and every group containing random and non-repeating numbers. How can I do this in excel?

Answer

How to use it

1. Open Excel & VBA editor (Alt+F11)


2. Insert the code below under Sheet1


3. Go back to Excel and select your desired range to fill with random & non-repeating numbers


4. Execute the macro (Alt+F8)

---

Sub randomNumbers()
    Low = Application.InputBox("Enter first valid value", Type:=1)
    High = Application.InputBox("Enter last valid value", Type:=1)
    Selection.Clear
    For Each cell In Selection.Cells
        If WorksheetFunction.CountA(Selection) = (High - Low + 1) Then Exit For
        Do
            rndNumber = Int((High - Low + 1) * Rnd() + Low)
        Loop Until Selection.Cells.Find(rndNumber, LookIn:=xlValues, lookat:=xlWhole) Is Nothing
        cell.Value = rndNumber
    Next
End Sub

Excel file to proof

^{I love those small and simple solutions so much}