The difference between the simple interest received from two different sources on Rs.12000 for 1.5 years is Rs. 720. What is the difference between their rates of interest?
S.I = PTR/100 (12000 x R1 x 1.5)/100 - (12000 x R2 x 1.5)/100 = 720 => 18000 (R1-R2) = 720 x 100 => (R1-R2) = `720xx(100/18000)` = 4%