a smartphone costing $500 is purchased using a credit card with a 10% annual interest rate. if the full…

a smartphone costing $500 is purchased using a credit card with a 10% annual interest rate. if the full payment is made within the 45 - day grace period, what is the total cost of the smartphone? formula: total cost = purchase amount + (purchase amount · interest rate)

a smartphone costing $500 is purchased using a credit card with a 10% annual interest rate. if the full payment is made within the 45 - day grace period, what is the total cost of the smartphone? formula: total cost = purchase amount + (purchase amount · interest rate)

Answer

Explanation:

Step1: Calculate the interest

The annual interest rate (r = 10%=0.1). The time (t=\frac{45}{365}) (assuming a non - leap year). The purchase amount (P = 500). The interest formula is (I=P\times r\times t). Substitute the values: (I = 500\times0.1\times\frac{45}{365}\approx5.07) (but since it's within the grace period, if the full payment is made within the grace period, the interest is (0) in many common credit - card grace - period policies (assuming the grace - period rule that no interest is charged if paid in full within the grace period)).

Step2: Calculate the total cost

Using the formula (C=\text{purchase amount}+I). Since (I = 0) (due to grace - period full - payment rule), (C=500 + 0).

Answer:

(500)