Problem: Simple interest rate of a bank was reduced to 5% from 7%. As a consequence, Karim’s income from bank interest was reduced by Tk. 2100 in 5 years. How much was Mr. Karim’s initial deposit with the bank?
View all: STANDARD BANK OFFICER (ATO) | WRITTEN QUESTION (MATH) SOLVE | 2016
Correct Answer: Deposit amount was 21,000 Tk.
Explanation:
Let, Karim’s total deposit = x TK
His interest gain at 7% interest = x $\times$ 7% x 5 (I = Pnr)
His interest gain at 5% interest = x $\times$ 5% x 5
According to the question, Difference of interest
(x$\times$7%$\times$S)-(x$\times$ 5%$\times$5)= 2,100
=> $\frac{35x}{100}-\frac{25x}{100}$ = 2100
=> $\frac{35x-25x}{100}$ = 2100
=> 10x = 2,100 x100
x = 21,000
