a certain sum of money is invested for 6 years in scheme A which is offers simple interest at a rate of 18.5% p.a. The simple interest obtained from scheme A is equal to the amount obtained when 3/4 times the same sum of money is invested in a different scheme B that also offer simple interest. if the sum is invested for 4 years in scheme B. what is the rate of interest p.a offered by scheme B.