Data Sufficiency (DS) | Re: A wooden rod is cut into two pieces. What is the length of the longer

A wooden rod is cut into two pieces. What is the length of the longer piece?
=> Longer piece = L
shorter piece = S


(1) One of the pieces is 20 inches longer than the other piece.
L = S+20 inch
as we don't know full length of wooden rod. => we don't know S to calculate L
Insufficient

(2) The length of the shorter piece is 1/3 the length of the longer piece
S= L/3
as we don't know full length of wooden rod. => we don't know S to calculate L
Insufficient

1+2
L = S+20 and L=S= L/3
=>
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