Question

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?

Answer 1

1. $ 0.15 increases for each dollar.

2. There is $ 0.20 increases for each dollar in the 20% column .

3. $ 48.75 is calculated for $325.00 in the 15% column.

$ 65 tip will be calculated in the 20% column for $ 325

Explanation:

a. The tip for each dollar would be

= $ 1 * (15%)

= $ 1 * 15/100

= $1 * 0.15

= $ 0.15

Therefore $ 0.15 increases for each dollar.

b. The tip for each dollar would be

= $ 1 * (20%)

= $ 1 * 20/100

= $1 * 0.20

= $ 0.20

There is $ 0.20 increases for each dollar in the 20% column .

c. The $ 325 bill can be broken down into

$ 100+ $100 + $100 +$25

The tip can be calculated

$ 100 * 15%+ $100* 15% + $100* 15% +$25* 15%

= $ 15+$ 15+$ 15+ $3.75

= $ 48.75

The tip can be calculated

$ 100 * 20%+ $100* 20% + $100* 20% +$25* 20%

= $ 20+$ 20+$ 20+ $5

= $ 65

$ 65 tip will be calculated in the 20% column for $ 325.