Question

krishna deposited rs 60000 at the rate of 8% in saving account After 5 years he withdrew rs 40000 and total interest of 5 years How long should he keep the remaining amount to get total interest rs 28800 from the beginning ​

Answer 1

The interest earned on an amount P deposited at an interest rate r for t years is given by the formula:

I = Prt

We can use this formula to calculate the total interest earned by Krishna in the first 5 years:

I1 = 600000.085 = 24000

After withdrawing Rs. 40000, Krishna has Rs. 20000 left in the account. Let's call the number of years he needs to keep this amount in the account to earn an additional interest of Rs. 28800 "t2". The interest earned on this amount is:

I2 = 200000.08t2

The total interest earned over the entire period is the sum of I1 and I2:

I1 + I2 = 24000 + 200000.08t2 = 24000 + 1600*t2

We want this total interest to be Rs. 28800, so we can set up the equation:

24000 + 1600*t2 = 28800

Solving for t2, we get:

1600*t2 = 4800

t2 = 3

Therefore, Krishna needs to keep the remaining Rs. 20000 in the account for an additional 3 years to earn a total interest of Rs. 28800 from the beginning.