Verified answer

Step-by-step explanation:

1.

To compute the simple interest on Php 800 for 9 months and 20 days at a rate of 15%, we first need to convert the time to a fraction of a year.

9 months and 20 days is equivalent to 9 + 20/30 = 9.67 months = 0.8058 years (assuming a year has 12 months).

The simple interest can be calculated using the formula:

Simple Interest = Principal x Rate x Time

Substituting the given values, we get:

Simple Interest = Php 800 x 0.15 x 0.8058

= Php 96.70

Therefore, the simple interest on Php 800 for 9 months and 20 days at a rate of 15% is Php 96.70.

2.

To determine the exact simple interest on Php 700 for the period January 20 to October 28, 2004, at 13% interest, we first need to calculate the time in years.

The number of days from January 20 to October 28, 2004, is 282 days. Since 2004 was a leap year, the total number of days in the year was 366. Therefore, the time in years is:

Time = 282/366 = 0.771

The simple interest can be calculated using the same formula as before:

Simple Interest = Principal x Rate x Time

Substituting the given values, we get:

Simple Interest = Php 700 x 0.13 x 0.771

= Php 74.31

Therefore, the exact simple interest on Php 700 for the period January 20 to October 28, 2004, at 13% interest is Php 74.31.