Try the following..
I am sure that will definitely help...

Sub WorkSheet1()
select case Range("A1").value
case 1
Rows("1:50").copy Sheets(2).Range("A1")
Case 2
Rows("1:100").copy Sheets(2).Range("A1")
Case 3
Rows("1:150").copy Sheets(2).Range("A1")
end select
msgbox "Complete!"
End sub

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