Question

at a certain rate of simple interest, a sum of money amounts to rs 6240 in 7 years and rs 7840 in 12 years. find the sum and rate of interest ​

Answer 1

Answer:

let money is xRs

x+interest of 7 years =6240

x+interest of 12 years =7840

subtract ing,interest of 5 years =(7840-6240)Rs

=1600Rs

1 year interest is 1600/5Rs=320Rs

7 years interest is 320×7Rs=2240Rs

principal amount is (6240-2240)Rs=4000Rs

rate of interest is

2240×100/4000×7 %=8%