6.4$
Solution:
Divide 40 and 100(there must always be 100 when solving percentage) then it would be equal to 0.4
after it Multiply it to 16
so we get 6.4.
Let

be the number of hours that the waitress works in the evening.
We know for our problem that she works

in the afternoon and that she works <span>1.75 hours less in the afternoon than in the evening, so:
</span>

<span>Since </span>

, we can rewrite our expression:


We can conclude that she works 3.375 hours in the evening, or expressed as a mixed fraction:

hours.
Using a system of equations, it is found that the unit prices are:
- $2.25 for a bag of chips.
- $1.50 for a liter of pop.
- $1.75 for a chocolate bar.
For the system:
- x is the unit price of a bag of chips.
- y is the unit price of liter of pop.
- z is the unit price for a chocolate bar.
From the table, the equations are:



Replacing the <u>first equation on the second and the third:</u>









Since
:




Then:


The unit prices are:
- $2.25 for a bag of chips.
- $1.50 for a liter of pop.
- $1.75 for a chocolate bar.
A similar problem, also solved using a system of equations, is given at brainly.com/question/14183076
The answer is c to your question