Time and Distance
Solved Examples -6
Conversion of miles into kilometer
5 miles = 8 km
Thus, 1 mile = 8/5 km
Or, 1 mile = 1.6 km
Solved Examples
Question (1) A car is running with a speed of 10 miles per hour. Find the speed in kilometer per hour.
(a) 10 km/h
(b) 12 km/h
(c) 14 km/h
(d) 16 km/h
Answer: (d) 16 km/h
Solution
Given, Speed of the car = 10 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 8/5 km
Thus, 10 miles `=\cancel(10)\ 2xx8/\cancel(5)`
= 2 × 8 = 16 kilometer
Thus, 10 miles per hour = 16 kilometer per hour Answer
Alternate Method to convert miles per hour into kilometer per hour
Given, Speed of the car = 10 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 1.6 km
Thus, 10 miles = 10 × 1.6 km
⇒ 10 miles = 16 km
Thus, 10 miles per hour = 16 kilometer per hour Answer
Question (2) A car is running with a speed of 15 miles per hour, thus find the its speed in kilometer per hour.
(a) 20 km/h
(b) 22 km/h
(c) 24 km/h
(d) 16 km/h
Answer: (c) 24 km/h
Solution
Given, Speed of the car = 15 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 8/5 km
Thus, 15 miles `=\cancel(15)\ 3xx8/\cancel(5)`
= 3 × 8 = 24 kilometer
Thus, 15 miles per hour = 24 kilometer per hour Answer
Alternate Method to convert miles per hour into kilometer per hour
Given, Speed of the car = 15 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 1.6 km
Thus, 15 miles = 15 × 1.6 km
⇒ 15 miles = 24 km
Thus, 15 miles per hour = 24 kilometer per hour Answer
Question (3) A car is running with a speed of 25 miles per hour. Find the speed in kilometer per hour.
(a) 20 km/h
(b) 30 km/h
(c) 40 km/h
(d) 50 km/h
Answer: (c) 40 km/h
Solution
Given, Speed of the car = 25 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 8/5 km
Thus, 25 miles `=\cancel(25)\ 5xx8/\cancel(5)`
= 5 × 8 = 40 kilometer
Thus, 25 miles per hour = 40 kilometer per hour Answer
Alternate Method to convert miles per hour into kilometer per hour
Given, Speed of the car = 25 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 1.6 km
Thus, 25 miles = 25 × 1.6 km
⇒ 25 miles = 40 km
Thus, 25 miles per hour = 40 kilometer per hour Answer
Question (4) The distance of Trento to New Jersey in USA is about 30 miles. What will its distance in kilometer?
(a) 40 km
(b) 42 km
(c) 44 km
(d) 48 km
Answer: (d) 48 km
Solution
Given, Distance from Trento to New Jersey in USA = 30 miles
Thus, distance in km = ?
We know that, 1 mile = 8/5 km
Thus, 30 miles `=\cancel(30)\ 6xx8/\cancel(5)`
= 6 × 8 = 48 kilometer
Thus, distance from Trento to New Jersey in USA = 48 kilometer Answer
Alternate Method to convert miles into kilometer
Given, Distance from Trento to New Jersey in USA = 30 miles
Thus, distance in km = ?
We know that, 1 mile = 1.6 km
Thus, 30 miles = 30 × 1.6 km
⇒ 30 miles = 48 km
Thus, distance from Trento to New Jersey in USA = 48 kilometer Answer
Question (5) A car is running with a speed of 35 miles per hour, thus find its speed in kilometer per hour.
(a) 50 km/h
(b) 54 km/h
(c) 56 km/h
(d) 60 km/h
Answer: (c) 56 km/h
Solution
Given, Speed of the car = 35 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 8/5 km
Thus, 35 miles `=\cancel(35)\ 7xx8/\cancel(5)`
= 7 × 8 = 56 kilometer
Thus, 35 miles per hour = 56 kilometer per hour Answer
Alternate Method to convert miles per hour into kilometer per hour
Given, Speed of the car = 35 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 1.6 km
Thus, 35 miles = 35 × 1.6 km
⇒ 35 miles = 56 km
Thus, 35 miles per hour = 56 kilometer per hour Answer
Question (6) A car is running with a speed of 40 miles per hour, thus find its speed in kilometer per hour.
(a) 54 km/h
(b) 64 km/h
(c) 68 km/h
(d) 72 km/h
Answer: (b) 64 km/h
Solution
Given, Speed of the car = 40 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 8/5 km
Thus, 40 miles `=\cancel(40)\ 8xx8/\cancel(5)`
= 8 × 8 = 64 kilometer
Thus, 40 miles per hour = 64 kilometer per hour Answer
Alternate Method to convert miles per hour into kilometer per hour
Given, Speed of the car = 40 miles per hour
Thus, speed in km/h = ?
We know that, 1 mile = 1.6 km
Thus, 40 miles = 40 × 1.6 km
⇒ 40 miles = 64 km
Thus, 40 miles per hour = 64 kilometer per hour Answer
Question (7) The distance from New York to San Francisco in USA is roughly 2900 miles. Calculate its distance in kilometer.
(a) 4640 km
(b) 4240 km
(c) 4040 km
(d) 4540 km
Answer: (a) 4640 km
Solution
Given, distance from New York to San Francisco in USA = 2900 miles
Thus, distance in km = ?
We know that, 1 mile = 8/5 km
Thus, 40 miles `=\cancel(2900)\ 580xx8/\cancel(5)`
= 580 × 8 = 4640 kilometer
Thus, distance from New York to San Francisco in USA = 4640 kilometer Answer
Alternate Method to convert miles into kilometer
Given, distance from New York to San Francisco in USA = 2900 miles
Thus, distance in km = ?
We know that, 1 mile = 1.6 km
Thus, 2900 miles = 2900 × 1.6 km
⇒ 2900 miles = 4640 km
Thus, distance from New York to San Francisco in USA = 4640 kilometer Answer
Question (8) The distance from New York to Atlanta, GA in USA is roughly 880 miles. Calculate its distance in kilometer.
(a) 1208 km
(b) 1308 km
(c) 1408 km
(d) 1508 km
Answer: (c) 1408 km
Solution
Given, distance from New York to Atlanta, GA in USA = 880 miles
Thus, distance in km = ?
We know that, 1 mile = 8/5 km
Thus, 40 miles `=\cancel(880)\ 176xx8/\cancel(5)`
= 176 × 8 = 1408 kilometer
Thus, distance from New York to Atlanta, GA in USA = 1408 kilometer Answer
Alternate Method to convert miles into kilometer
Given, the distance from New York to Atlanta in USA = 880 miles per hour
Thus, distance in km = ?
We know that, 1 mile = 1.6 km
Thus, 880 miles = 880 × 1.6 km
⇒ 880 miles = 1408 km
Thus, the distance from New York to Atlanta in USA = 1408 kilometer Answer
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