Question

Ravi goes to college from his village at the speed of 5km/h and returns at the speed of 4km/h. If he takes 9 hours in all, find the distance (in km) between the village and the college.

• A. 20
• B. 40
• C. 18
• D. 9

Answer 1

Answer:

A. 20

Let the distance between the village and the college be (x) km.

Time taken to go to college:

$\frac{x}{5}$

Time taken to return:

$\frac{x}{4}$

Total time = 9 hours

$\frac{x}{5}+\frac{x}{4}=9$

LCM of 5 and 4 is 20:

$\frac{4x+5x}{20}=9$

$\frac{9x}{20}=9$

9x=180
x=20

Distance between the village and the college = 20 km