Time and Distance - Arithmetic

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

= 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

= 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

= 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

= 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

= 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

= 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

= 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

= 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