Failing to understand this simple yet inexplicable percentage problem

Question

For example the borrowed amount is 25000000. Now let's say the interest rate for the year is 15%. Which makes it 1.25% per month. If the Sum was borrowed on the 6th of January, 2016. For the purpose of easier Interest calculation later on. The concerned party decided to pay interest till 31st March, 2016 and then monthly

which makes it 86 days if you also include the day on which the sum was borrowed

 

Lets Say One calculates the interest to be collected as

 

25000000 * 15% * 86/365 = 883561.6

 

 

 

 

 

Whereas the other 

 

2500000* 1.25%= 312500

 

312500/30=10416.67

 

10416.67*86= 895833.3

 

 

 

so the difference between the two is of 12272.33

 

Why is that ?

When both agree on the number of days

Both have agreed on the Interest Rate 

 

Answer 1

Well 365/12 = 30.4, so you need to divide the $312,500 by 30.4 vice by 30 and you'll get $10,274 per day (instead of $10,416.67).  Then ($10,274 per day)*(86 days) = $883,561.64 and we're in agreement.