Rohan can travel from Delhi to Kanyakumari in 30 h. If he reduces his speed by $$\frac{1}{15}$$​th, he will go 10 km less in the same time. His speed is:

Correct option is C

Given:

Rohan can travel from Delhi to Kanyakumari in 30 hours.

If he reduces his speed by $$\frac{1}{15}$$​, he will travel 10 km less in the same time.

Formula Used:

Distance = Speed × Time

Solution: 

Let the speed of Rohan = x

Distance = x × 30 

Reduce his speed $$\frac1{15}$$​

Remaining Speed = x - $$\frac{1x}{15}$$  = $$\frac{14x}{15}$$​​

Distance = $$\frac{14x}{15} \times 30$$​

The difference between the two distances is 10 km

​$$x \times 30 - \frac{14x}{15} \times 30$$​ = 10

30x $$- 30 \times \frac{14x}{15}$$​ = 10

30x - 28x = 10

2x = 10

x = 5

5 km/h