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:
Hence x = -1 and y = 18
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Step-by-step explanation:
Given the system of equations
y + 8x = 10... 1
2y - 4x = 40 ... 2
From 1; y = 10-8x
Substitute into 2;
2(10-8x) - 4x = 40
20 - 16x - 4x = 40
20 - 20x = 40
-20x = 40 - 20
-20x = 20
x = -1
Recall that y = 10-8x
y = 10 - 8(-1)
y = 10 + 8
y = 18
Hence x = -1 and y = 18
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-7x + 6 =27
subtract 6 from both sides
-7x =21
divide both sides by -7
x= -3
First 8.58
Second 8.508
Third 7.5
Fourth 7.058
