Let the C.P. of the item for Rohit be Rs x
We know that,
S.P.=C.P.×(1+Profit %100)
⇒660=x×(1+10100)
⇒660=x×110100
⇒x=660×100110=600
⇒ Rohit buys the item at Rs 600 i.e., the price at which the item was sold to Rohit is Rs 600
Now, M.P.=(S.P.×100100−Discount %)
=600×100100−25
=600×10075
=Rs 800
Hence, the marked price of the item is Rs 800.