No, There won't be any retransmissions on time out. It is SR with NAK.
Reason: See here, in this question , the transmission is said to be successful if there is no NAK( negatively acknowledged ). And it is clearly stated that ACK (+ve ACK) frames never occur. That is even if the whole window (every packet) is successfully received, the receiver won't send anything. Thus accordingly sender must be configured not to retransmit on time out . Actually , time out here signifies successful transmission.
now my solution :
the fraction of overhead in transmission
i.e 1.9%