Question

Lucy goes out to lunch. the bill, before tax and tip, was $12.70. a sales tax of 6.5% was added on. lucy tipped 18% on the amount after the sales tax was added. the total cost of the meal plus tip and tax was more than the cost of the bill by what percent? round to the nearest whole number.

Answer 1

26%

Explanation:

Adding r% to a bill is equivalent to multiplying the amount by (1 +r%). Each resulting amount is rounded to the nearest penny.

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tax

After the 6.5% tax was added, the bill was ...

$12.70 × (1 +0.065) = $13.5255 ≈ $13.53

tip

After the 18% tip was added to this amount, the total cost was ...

$13.53 × (1 +0.18) = $15.9654 ≈ $15.97

total

Then the multiplier of the original bill was ...

$15.97/$12.70 ≈ 1.25748... ≈ (1 +25.7%)

The total cost was about 26% more than the original bill.