a sum of money at simple interest amounts to 24000 in 4 years if the rate of interest is increased by 20% the same sum amounts to 25800 in same time the original rate of interest

let “P” be the principal. let “R” is the original interest rate in percentage P{ 1 + ( 4*R/100)} = 24000 If “1.2 R” is the increased interest rate in percentage. Then, P{ 1 + (4*1.2*R/100} = 25800 On solving the above two equations, we get Principle = 15000; R = 15%