Raj and Vikram are two travelers in ancient India, walking along the Silk road. On the first day of travel, Raj travels 5 yojanas, and on each successive day travels 3 yojanas more than the previous day. Vikram started at the same place and travels the same path, but started 5 days earlier, and travels 7 yojanas a day. On which day of Raj's travel will the two of them meet?

Solve the first question I ask on 42 km perhour on 7 litres of petrol,how far will it travels on 12 litres