US dollar ends tad cheaper against rupee

The US dollar ended marginally cheaper against the rupee at 66.65/66 per dollar and the pound sterling also finished lower at Rs 86.39/41 per pound at the close of the Interbank Foreign Exchange market today.
Following are the Interbank Forex and RBI rates:
(In Rs Per Unit)
Unit Interbank RBI Reference US Dollar 66.65/66 US Dollar Rs. 66.6519 Pound Sterling 86.39/41 Euro Rs. 74.6701 Euro 74.75/77
Japanese Yen(100) 66.