Option Explicit
Sub Test()
Dim i As Byte, y() As Variant, z() As Variant, x As Integer, c As New Collection
Randomize
y = Array(16, 17, 18)
z = Array(9, 25, 42)
For i = 0 To 2
Do While c.Count < 3
x = Int(y(i) * Rnd + z(i))
If Cells(x, 3) = 1 Then
On Error Resume Next
c.Add Cells(x, 3).Address, CStr(Cells(x, 3).Address)
If Err = 0 Then
With Sheets("Mois en cours").Range("F4")
.Value = .Value & Cells(x, 3).Address(0, 0) & vbLf
End With
End If
On Error GoTo 0
End If
Loop
Set c = Nothing
Next i
End Sub