Krishna deposited rs 60000 at the rate of 8% in saving account. after 5 yrs he withdrew rs 40000 and total interest of 5 yrs. how long should he keep the remaining amount to get total interest rs 28000 from the beginning...

22.5 years

Step-by-step explanation:

we know that

The simple interest formula is equal to

where

I is the Final Interest Value

P is the Principal amount of money to be invested

r is the rate of interest  

t is Number of Time Periods

in this problem we have

substitute in the formula above

Remember that

Krishna withdrew Rs 40000 and total interest

The remaining amount is

Now

we have

substitute

solve for t

From the beginning adds 5 years

option a is correct.

step-by-step explanation:

scale factor: it is used to find proportional measurements.

proportions means having the same ratio.

scale factor is the ratio of the model measurement to the actual measurement in a simplest form.

or we can say that the ratio of any two corresponding lengths in two similar geometric figures

if the scale factor is more than 1, then it is an enlargement,

if the scale factor less than 1, then it is a reduction.

given the two geometric figure:

by definition of proportions, we have