Question

the simple interest on a certain sum for 4 years at 9% per annum is less than 216 than the simple interest on the same sum for 3 years at 18% per annum.find the sum

Answer 1

difference=216
first simple intrest=(p×r×t)/100
=(p×9×4)/100
=9p/25

second simple intrest=p×r×t/100
=p×18×3/100
=27p/50

then;
27p/50-9p/25=216
=(27p-18p)/50=216
=9p/50=216
= p= 216×50/9
p=24×50
=p= 1200