Answer:
The rate of the boat in still water is 40 miles per hour
The rate of the current is 10 miles per hour
Step-by-step explanation:
we know that
The speed or rate is equal to divide the distance by the time
Let
x ----> the rate of the current (miles per hour)
y ----> the rate of the boat in still water (miles per hour)
we have that
<em>going upstream </em>
----> equation A
<em>going downstream </em>
----> equation B
Solve the system of equations by elimination
Adds equation A and equation B
<em>Find the value of x </em>
therefore
The rate of the boat in still water is 40 miles per hour
The rate of the current is 10 miles per hour
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
2(5)^2+10
2(25)+10
50+10
60
Yes
The area of the parallelogram with a height of 13cm and base 20cm is 260cm².
<h3>
How to find area of a parallelogram?</h3>
A parallelogram is simply a quadrilateral with two pairs of parallel sides.
The area of a parallelogram is expressed as;
A = base × height
Given the data in the diagram;
- Height of the parallelogram = 13cm
- Base of the parallelogram = 20cm
- Area of the parallelogram = ?
Plug the given values into the equation above and solve for A.
A = base × height
A = 20cm × 13cm
A = 260cm²
The area of the parallelogram with a height of 13cm and base 20cm is 260cm².
Learn more about parallelogram here: brainly.com/question/1563728
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Answer:
301.59
Step-by-step explanation:
your answer was almost right you just forgot to multiply by 9
