A and B borrowed a tractor for 23 days. A ploughed 12 acres per day for a certain number of days and then Bused it to plough 15 acres per day for the remaining days. If they paid Rs 3,000 and Rs 2,000 respectively, for how many days did A use the tractor?

How many cubes of 10 cm edge can be put in a cubical box of 1 m edge.

The wheel of a motorcycle, 70 cm in diameter makes 40 revolutions in every 10 seconds. What is the speed of the motorcycle in km/hr