6. marilyn carries a tip-calculator card with her. it lists the amounts
for 15% and 20% tips on whole-dollar values up to $100.00. her
daughter notices a pattern. she says, "for each dollar the cost
increases, the tips in the 15% column increase by $.15."
a. explain why this pattern occurs for 15%-tip values.
b. for each dollar increase, what is the amount of increase in the
20% column?
c. the tip-calculator card only goes up to $100.00. how can you use
the card if your restaurant bill totals $325.00?