Well, you can do Aggregate (Totals) queries, which group records by certain fields, and then take mathematical functions of other fields (like SUM, COUNT, MAX, MIN, etc).
So if you are simply just trying to sum up the Cash Sale and Total Amount fields for each Fuel Type, you would create an Aggregate Query where you Group on FuelType and Sum the Cash Sale and Total Amount fields.
Note that you cannot add any of the other fields in this query, as every field in an Aggregate Query must either be included in the Grouping, or have an Aggregate function applied to it.
Thanks Joe, Let me try this. I will drop a reply here if I face any difficulties.