An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (1)
Calculate the trade-in value: T r a d e _ in _ v a l u e = 0.80 × $6 , 591 = $5 , 272.80 .
Calculate the price after trade-in: P r i ce _ a f t er _ t r a d e _ in = $21 , 450 − $5 , 272.80 = $16 , 177.20 .
Calculate the total cost before financing: T o t a l _ cos t _ b e f ore _ f inan c in g = $16 , 177.20 + $1 , 475.76 + $1 , 089 + $124 = $18 , 865.96 .
Calculate the percentage of interest: P erce n t a g e _ in t eres t = $22 , 649.40 $3 , 783.44 × 100 = 16.70% . The answer is 16.70% .
Explanation
Calculate Trade-in Value First, we need to find the trade-in value of Charles's 2004 Dodge Neon. According to the table, the listed price for a 2004 Dodge Neon in good condition is $6 , 591 . The dealer gives Charles 80% of this price.
Determine Trade-in Value The trade-in value is calculated as follows: T r a d e _ in _ v a l u e = 0.80 × $6 , 591 = $5 , 272.80
Calculate Price After Trade-in Next, we calculate the price of the new car after the trade-in: P r i ce _ a f t er _ t r a d e _ in = $21 , 450 − $5 , 272.80 = $16 , 177.20
Calculate Sales Tax Now, we need to calculate the sales tax, which is 6.88% of the list price of the new car: S a l es _ t a x = 0.0688 × $21 , 450 = $1 , 475.76
Calculate Total Cost Before Financing We then calculate the total cost of the car before financing by adding the price after trade-in, sales tax, vehicle registration fee, and documentation fee: T o t a l _ cos t _ b e f ore _ f inan c in g = $16 , 177.20 + $1 , 475.76 + $1 , 089 + $124 = $18 , 865.96
Calculate Monthly Interest Rate The annual interest rate is 12.28% , so the monthly interest rate is: M o n t h l y _ in t eres t _ r a t e = 12 0.1228 = 0.01023333
Calculate Monthly Payment We use the loan formula to calculate the monthly payment: M = P ( 1 + i ) n − 1 i ( 1 + i ) n Where: M = Monthly payment P = Principal loan amount ( $18 , 865.96 ) i = M o n t h l y in t eres t r a t e ( 0.01023333 ) n = N u mb ero f m o n t h s ( 36 ) M = $18 , 865.96 ( 1 + 0.01023333 ) 36 − 1 0.01023333 ( 1 + 0.01023333 ) 36 = $629.15 $
Calculate Total Amount Paid The total amount paid over the three years is: T o t a l _ am o u n t _ p ai d = $629.15 × 36 = $22 , 649.40
Calculate Total Interest Paid The total interest paid is: T o t a l _ in t eres t _ p ai d = $22 , 649.40 − $18 , 865.96 = $3 , 783.44
Calculate Percentage of Interest Finally, we calculate the percentage of the total amount paid that is interest: P erce n t a g e _ in t eres t = $22 , 649.40 $3 , 783.44 × 100 = 16.70%
Examples
Understanding loan calculations is essential when making significant purchases like a car or a house. For example, if you're buying a house, knowing how the interest rate, loan term, and principal amount affect your monthly payments and the total interest paid can help you make informed decisions and choose the best loan option for your financial situation. This also helps in budgeting and planning your finances effectively over the loan's duration.
