Overright Repo vs 2-year Repo Duration -EOC Reading 23 Q 13 -Can someone please explain this?

CFA Level III Fixed Income
#1
  1. The 2-year term leverage would shorten the total duration of the levered portfolio relative to overnight repo by the dollar duration of the 2-year liability. The levered portfolio duration would be longer using overnight repo because its proceeds are being invested in bonds to have the same duration as the unlevered portfolio—thus the net effect is a longer duration because the overnight repo duration is zero.

Don’t understand…How come the net effect is a longer duarion because the overnight repo duration is zero?

#2

answered multiple times before

What is duration of equity

(A*DA - L*DL)/E -> When the Repo is a 2 year team - (A*DA - L*2) / E

when Repo is overnight -> it is (A*DA - L*0) / E - which is a bigger number

#3

Edit: cpk provided a cleaner answer than I did.