21.
If the banker’s discount on a certain amount of money is Rs. 80 and the true discount on the same amount for the same time duration is Rs. 64, then the amount due is:

22.
Find the banker’s gain, if the present worth of a certain amount is Rs.2400 and the true discount is Rs.120.

23.
Find the rate percent if the banker’s gain on a certain sum due two and a half year hence is $$\frac{1}{5}$$ of the banker’s discount.

24.
The banker’s gain on a bill due 2 years hence at 10% per annum is Rs.10. What is the true discount?

25.
What is the banker’s discount, if the true discount on a bill of Rs. 840 is Rs.105?