Question

3. A clerk starts from his house with a speed of 2 km h and
reaches the office 3 min late. Next day he increases speed
1 km h and reaches the office 3 min earlier. Find the
distance between his house and office.
(a) 1 km
(b) 0.6 km
(c) 2 km
(d) 3 km​

Answer 1

Answer:

Let distance be x . Exact office time be t.

Now calculate time *(and convert it to minutes)

$\frac{x}{2} \times 60 = t + 3 \\ \\ \frac{x}{3} \times 60 = t - 3$

Subtract both

$60x( \frac{1}{2} - \frac{1}{3} ) = 6 \\ 60x = 24 \\ x = \frac{36}{60} = 0.6km$