Problem: The simple interest on a certain sum of money for 2$\frac{1}{2}$ years at 12% per annum is Tk. 40 less than the simple interest on the same sum for 3$\frac{1}{2}$ years at 10% per annum. Find the sum.
View all: PUBALI BANK OFFICER (SO)| WRITTEN QUESTION (MATH) SOLVE | 2016
Correct Answer: 800
Explanation:
ধরি, আসল x টাকা
প্রশ্নমতে, x $\times10\%\times\frac{7}{2}-x\times12\%\times\frac{5}{2}$=40
=>$\frac{x\times7\times10}{200}-\frac{x\times 12\times 5}{200}$ = 40
=> $\frac{70x}{200}-\frac{60x}{200}$ = 40
=> $\frac{70x-60x}{200}$ = 40
=> 10x = 40$\times$200
x = 800
