Posted by JrUNCFan on .
on march 8, you sign a $4000 note with simple interest 10% for 240 days. You make partial payments of $1300 on May 26 and $2300 on july 31. How much will you owe on the date of maturity (November 3)?
Please show work!!!

Survey of Math 140 
Kate,
First calculate the number of days between March 8 and May 26. 24 days in March, 30 days in April, and 26 days in May. Add those together=80 days.
4000(1+.10)^(80/365)= 4084.44. This is how much you owe on May 26, before the $1300 payment.
Then subtract 4084.441300. This is your new balance. 2784.44
Now calculate the days between May 26 and July 31. 4 days in May, 30 in June, 31 in July. This is 65 days.
2784.44(1+.10)^(65/365)=2832.10 This your balance on July 31st before making payment. Now subtract 2300. 2832.102300=532.10 Now calculate the number of days between July 31st and November 3rd=95 days.
532.10(1+.10)^(95/365)=545.46. This is how much you owe on November 3rd. 
Survey of Math 140 
JrUNCFan,
545.46 is not one of the choices that i have to choose from. the choices are 553.11, 555.05, 544.98, and 557.88

Survey of Math 140 
Kate,
sorry. you could try changing the 80 to 79 in the first part. I was debating with myself, which one to use.

Survey of Math 140 
helper,
Simple interest
10% = 0.1 /365 = 0.000274 daily interest
3/8 to 5/26 = 79 days
79 * 0.000274 = 0.021646 (79 day interest rate) * $4000 = $86.58 interest this period
5/27 to 7/31 = 65 days
65 * 0.000274 = 0.01781 (65 day interest rate) * $2700 ($4000  1300) = 48.08 interest this period
8/1 to 11/3 = 94 day
94 * 0.000274 = 0.025757 (94 day interest rate) * $400 $2700  2300) = $10.30 interest this period
Payment on 11/03 $400 + interest =
$400.00 + 86.58 + 48.08 + 10.30 = 544.96 
Survey of Math 140 
towanda,
convert the numeral to a numeral in base ten
43,163ten