Question 1:
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Total points = 100
Total question = 40
Type of questions : 2-points question and 4-points questions
Assumed all 40 questions are 2-points questions.
Total points = 40 x 2 = 80
Difference in points = 100 - 80 = 20 points
Difference in the 2 type of questions = 4 - 2 = 2
Number of 4 marks questions = 20 ÷ 2 = 10
Number of 2 marks questions = 40 - 10 = 30
Answer: There are 10 4-marks questions and 30 2-marks questions.
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Question 2:
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Let x be the number of offices you need to clean.
Total cost = 315 + 4x
Total revenue = 25x
To break even,
315 + 4x = 25x
21x = 315
x = 15
Answer: You need to clean 15 offices to break even.
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Question 3:
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Total distance (including return trip) = 255 + 255 = 510 miles
Total time taken = 1.7 + 1.5 = 3.2 hours
Speed = Distance ÷ time
Speed = 510 ÷ 3.2 = 159.38 miles/hour
Answer: The average speed is 159.38 miles/hour
Answer: 432 units²
Step-by-step explanation:
The figure is composed by two trapezoids.
The formula for calculate the area of a trapezoid is:
Where "B" is the larger base, "b" is the smaller base and "h" is the height.
Let be 
the area of the figure, 
the area of the trapezoid on the left and 
the area of the trapezoid of the right. Then the area of the figure will be:
Substituting values, you get:
<h3> </h3>
45 = 90% * x
45 = .90x
45/.90 = x
x = 50
45 is 90% of 50
