An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
Approximately 2.81 x 10^21 electrons flow through the device that delivers a current of 15.0 A for 30 seconds. This is calculated by first determining the total charge and then dividing it by the charge of a single electron. The total charge flowing is 450 coulombs.
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Calculate EECU's monthly ATM fee: (5 - 2) * $2 = $6.
Calculate E-town Bank's monthly ATM fee: 5 * $2 = $10.
Determine monthly savings: $2.50 (monthly fee) + ($10 - $6) (ATM fee difference) = $6.50.
Calculate annual savings: 6.50 ∗ 12 = \boxed{$78}.
Explanation
Problem Analysis Let's break down Barry's potential savings by choosing EECU over E-town Bank. We'll consider the monthly fees and ATM usage fees for each bank to determine the annual savings.
EECU ATM Fees First, let's calculate the monthly ATM fees for EECU. Barry uses network ATMs 5 times a month, and EECU offers 2 free transactions. So, he pays for 5 - 2 = 3 transactions. At $2 per transaction, his monthly ATM fee with EECU is 3 * $2 = $6.
E-town Bank ATM Fees Next, let's calculate the monthly ATM fees for E-town Bank. Barry uses network ATMs 5 times a month, and E-town Bank charges $2 for each transaction. So, his monthly ATM fee with E-town Bank is 5 * $2 = $10.
Monthly Savings Now, let's calculate the monthly savings. EECU has no monthly fee, while E-town Bank charges $2.50 per month. The difference in ATM fees is $10 - $6 = $4. So, Barry saves $2.50 (monthly fee) + $4 (ATM fee difference) = $6.50 per month by choosing EECU.
Annual Savings Finally, let's calculate the annual savings. Barry saves $6.50 per month, so his annual savings are $6.50 * 12 = $78.
Conclusion Therefore, Barry can reasonably expect to save $78 annually by choosing EECU over E-town Bank.
Examples
Imagine you're deciding between two phone plans. One has a low monthly fee but charges extra for data, while the other has a higher monthly fee but includes more data. By calculating your average data usage and comparing the total costs of each plan, you can determine which plan offers the best value for your needs. This is similar to Barry's situation, where he's comparing bank fees to minimize his expenses. Understanding how to analyze and compare costs can help you make informed decisions in various financial situations.
