1.  The banker's discount on Rs. 1600 at 15% per annum is the same as true discount on Rs. 1680 for the same time and at the same rate. The time is: 


2.  The banker's discount on a bill due 4 months hence at 15% is Rs. 420. The true discount is: 


3.  The banker's gain on a sum due 3 years hence at 12% per annum is Rs. 270. The banker's discount is: 


4.  The banker's gain of a certain sum due 2 years hence at 10% per annum is Rs. 24. The present worth is: 


5.  The banker's discount on a sum of money for 1 years is Rs. 558 and the true discount on the same sum for 2 years is Rs. 600. The rate percent is: 

