When Geeta increases her speed from 12 km/hr to 20 km/hr, she takes one hour less than the usual time to cover the distance between her home and office. The distance between her home and office is________km.

Let the time taken by Geeta usually be $$t$$ hours.

Now, when Geeta is walking at a speed of 12 km/hr, time taken = $$t$$ hours.

So, Distance covered =$$12t$$ km

Also, when Geeta is walking at a speed of 20 km/hr, time taken = $$(t-1)$$ hours.

So, Distance covered = $$20\cdot(t-1)$$ km

Now, distance covered in both the cases is same.

So, $$12\cdot t=20\cdot(t-1)$$

or, $$8\cdot t=20$$

or, $$t=2.5$$ hours

So, distance between her home and office is $$12\times\ 2.5=30$$ km