Instruction: Read and answer the following questions: i A car traveled 281 miles in 4 hours 41 minutes. What was the average speed of the car in miles per hour?
ii. In a group of 120 people, 90 have an age of more 30 years, and the others have an age of less than 20 years. If a person is selected at random from this group, what is the probability the person's age is less than 20?
iii-The length of a rectangle is four times its width. If the area is 100 m2 what is the length of the rectangle?
Answers
1}⇒ Average Speed = Total Distance/ Total Time
Total distance = 281 miles
Total Time = 4 hours and 41 min
we will convert the minute in hours = 41/60 = 0.683 hour
So total time will be = 4 + 0.683 = 4.683 hours
Average speed = 281/4.683 = 60.004 Miles/hour.
1 Mile / Hour = 1.60934 Km / Hour.
60.004 Miles / hour = 96.567 Km / hour
--------------------------------------
2} ⇒ 30 people have an age less than 20 years.
30 out of 120. this means you can do this relationship:
If 30 out of 120 are less than 20 years old, then picking one at random will yield you with a 1 in 4 chance or 25% chance of picking someone leas than 20 years old.
--------------------------------------
3} ⇒The area of the rectangle = length × breadth
Letting the width = x m
Then, length = 4x m
A = l × b = 100 m²
4x × x = 100 m²
x² = 100/4 m²; then removing the squares
x = 10/2 m
x = 5 m = width
Length = 20 m