Question

1. guided problem solving your lunch bill is $19.75. a 5% sales tax will be added, and you want to give a tip of about 20% of $19.75. estimate how much you will pay for lunch.

• to what number should you round the bill?
• about how much tip should you give?

Explanation:

Step1: Round the bill to nearest whole number

Round $\$19.75$ to $\$20$.

Step2: Calculate 5% sales tax on rounded bill

$5\% \text{ of } 20 = 0.05 \times 20 = \$1$

Step3: Calculate 20% tip on rounded bill

$20\% \text{ of } 20 = 0.20 \times 20 = \$4$

Step4: Sum total cost

$\$20 + \$1 + \$4 = \$25$

Step5: Answer subquestion 1

Rounded bill target is $\$20$.

Step6: Answer subquestion 2

Estimated tip is $\$4$.

Answer:

• You should round the bill to $\$20$.
• You should give about $\$4$ in tip.
• The estimated total amount to pay is $\$25$.