Question 84

If I walk at 7/6 of my usual speed, then I reach my office 15 minutes early. What is the usual time taken (in minutes) by me to reach the office?

Solution

Let my usual speed = $$6x$$ km/min and my usual time to reach office = $$t$$ minutes

New speed = $$\frac{7}{6}\times6x=7x$$ km/min and new time = $$(t-15)$$ minutes

$$\because speed\propto\frac{1}{time}$$

=> $$\frac{6x}{7x}=\frac{(t-15)}{t}$$

=> $$\frac{6}{7}=\frac{t-15}{t}$$

=> $$6t=7t-105$$

=> $$7t-6t=t=105$$ minutes

=> Ans - (D)

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: