A sum of money, put at simple interest doubles itself in 8 years. The same sum will triple itself in:

1. 16 years

2. 12 years

3. 24 years

4. 18 years

₹ 5,000 earns ₹ 500 as simple interest in 2 years. Then the rate of interest is

1. 10%

2. 5%

3. 20%

4. 2%

Find the interest and the amount on:

₹ 750 in 3 years 4 months at 10% per annum.

Find the interest and the amount on:

₹ 5,000 at 8% per year from 23rd December 2011 to 29th July 2012.