Rounding off Decimal Digits only

Dear experts,
I want a formula which will round off the decimal digits in multiples of 0.05 or 0.00 based on criteria.For eg,
If the Number is, Excel formula should round off as
7.60,7.60
7.61,7.60
7.62,7.60
7.63,7.65
7.64,7.65
7.65,7.65
7.66,7.65
7.67,7.65
7.68,7.70
7.69,7.70
7.70,7.70

Thus the logic is:
If the Unit place of decimal digit is between 0 to 2 then Round off in mulatiple of 0 (Zero)
If the Unit place of decimal digit is between 3 to 7 then Round off in mulatiple of 0.05 (Zero)
If the Unit place of decimal digit is greater than 0, then Round off in mulatiple of next higher 0 (Zero) level ie 7.68 becomes 7.70, 7.88 becomes 7.90, 7.98 becomes 8.00 and so on like this.

How can this be done with formula?
Youe help will really benefit me a lot.

Thanks and regards
Sujit Talukder

Thank you daddylonglegs,
Many Many thanks.
Its so simple and I wasted last 1 day to come out with solution.

Once again, thank you.