Find the rates of interest per year, if the interest charged for 8 months be 0.06 times of the money borrowed.

In how many years will ₹ 950 produce ₹ 399 as simple interest at 7% ?

What sum of money borrowed on 24th May will amount to ₹ 10,210.20 on 17th October of the same year at 5 percent per annum simple interest?