If on an average, 20% rate of interest was charged on borrowed funds, then the total borrowed funds used by this company is the given 2 yr amounted to

From 1990 - 91 : Interest is 39 lakhs
From 1991 - 92 : Interest is 64 lakhs
So, Total interest in 2 years is 39 + 64 = 103 lakhs

Now, it is mentioned in the question that interest was calculated on 20% of borrowed fund.

So, 20% of borrowed fund = 103 lakhs
And, Borrowed fund = (103 × 100) / 20 = 515 lakhs

From 1990 - 91 : Interest is 39 lakhs
From 1991 - 92 : Interest is 64 lakhs
So, Total interest in 2 years is 39 + 64 = 103 lakhs
Now, it is mentioned in the question that interest is calculated on 20% of borrowed fund.

So, 20% of borrowed fund = 103 lakhs
And borrowed fund = (103 × 100) / 20 = 515 lakhs

Why have they taken the reciprocal of 20% ? And instead of doing this 103×20÷100 why have they done this way 103×100÷20 ??