Problem
Dan is comparing offers from two banks on checking accounts that include debit cards. Bank A charges a \$10 monthly fee for a checking account and debit card, plus \$0.80 for each transaction. Bank B charges a \$25 monthly fee for a checking account and debit card, plus $\$ 0.20$ for each transaction. Suppose Dan makes 30 transactions in a given month. Answer the questions below. (a) How much would he pay at each bank for the given month? Bank A: $S \mathbb{1}$ Bank B: $S \square$ (b) For the given month, which bank is cheaper and by how much? Bank A Bank A is S Cheaper than Bank B. Bank B Bank $B$ is $S \square$ cheaper than Bank A. Explanation Check
Solution
Step 1 ：\(S1 = 10 + 0.80 \times 30 = 10 + 24 = 34\)
Step 2 ：\(S2 = 25 + 0.20 \times 30 = 25 + 6 = 31\)
Step 3 ：Comparing \(S1\) and \(S2\), we find that Bank B is cheaper than Bank A.
Step 4 ：The difference in cost between the two banks is \(\Delta = S1 - S2 = 34 - 31 = 3\)
Step 5 ：\(\boxed{\text{Bank A: } S1 = 34}\)
Step 6 ：\(\boxed{\text{Bank B: } S2 = 31}\)
Step 7 ：\(\boxed{\text{Bank B is } 3 \text{ cheaper than Bank A.}}\)
