Simple interest used for odd periods

Question

An amount of 10 000 was invested in a special savings account on 15 May at an interest rate of 15% per annum compounded quarterly for 7 months. Interst is calculated on 1 January, 1 April, 1 July and 1 October every year. If the simple is used for the odd periods and compound interest for the rest of the term, the amount of interest received after 7 months equals?? And if fractional compounding is used for the full term of 7 months, the total amount of interest received will equal??

Answer 1

with quarter kompound, 6 months=2 quarters

15%/yeer = (15/4) per quarter=3.75% or 1.0375^2=1.07640625

1.07640625*10,000=10,764.0625$...so interest=764.0625$

1 month simpel interest...15%/12=1.25%

0.0125*10,000$=125$