# Math

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I posted this problem last night and someone answered. I followed all the steps that this person told me to do and I don't get the right answer. The right answer is suppose to be \$23.54. What am I doing wrong?

For groups of four or more diners, many restaurants add a 15% gratuity and a tax of 8% to the bill. If the bill (including gratuity and tax) for four people came to \$193, how much was the tip?

assume the 8% tax is added first, then the 15% tip.

So, first, add 8% to the bill amount to get a subtotal

subtotal = 193 + 0.08(193)

The same thing can be done more succinctly as follows:

subtotal = 1.08(193) \$208.44

Then take 15% of that to determine the top:

tip = 0.15(subtotal)

To chain it all together:
tip = 0.15(1.08(193)) When you do this it comes to 31.26 that's not the right answer.

• Math -

let the bill before taxes and tips be \$x
then (1.15)(1.08)x = 193
x = 193/((1.15)(1.08))
= 155.39

After tax, bill was 155.39(1.08) = 167.83

now 15% of that is 25.17

so the tip was 25.17

check: [155.39 + .08(155.39)])1.15) = 193

• Math -

1. The School Action Society asked its members how many hours they had worked during the previous week in part-time jobs. The following data lists the number of hours spent working during the previous week.

6 6 6 4 6 6 9 8 6 3 7 6
6 7 6 6 7 6 6 8 6 7 8 4

a. From these data construct a frequency table with the included columns.
(References: example 1 and 2 page 41, end of section exercises 27, 28 page 51). Round the relative frequencies to three decimal places. (5 points)

Hours Tally Frequency
f Midpoint Relative Frequency
3 - 4 2.5
5 - 6
7 - 8
9 - 10