Answer:
8 maths tests
Step-by-step explanation:
Given data
We are told that in 1/4 hour that is 0.25hour (15 mins) She grades 1 math test
our aim is to find how many maths test she grade in 3 hours (120min)
Hence
in 15 mins she does 1 grading
in 120 mins she does x
cross multiply
15x= 120
divide both sides by 15
x= 120/15
x= 8 maths test
Hence in 2 hours, she can grade 8 maths tests
Answer:
see attached diagram
Step-by-step explanation:
First, draw the dashed line 50x+150y=1500 (dashed because the inequality is without notion "or equal to"). You can do it finding x and y intercepts.
When x=0, then 150y=1500, y=10.
When y=0, then 50x=1500, x=30.
Connect points (0,10) and (30,0) to get needed dashed line.
Then determine which region (semiplane) you have to choose. Note that origin's coordinates (0,0) do not satisfy the inequality 50x + 150y>1500, because

This means that origin lies outside the needed region, so you have to choose the semiplane that do not contain origin (see attached diagram).
Answer:
$82.57
Step-by-step explanation:
The tip they leave is ...
$78.64 × 0.20 = $15.73
The amount of the discount is ...
$78.64 × 0.15 = $11.80
Then the total cost of the meal and tip is ...
meal price - discount + tip
$78.64 -11.80 +15.73 = $82.57