Susan made $\$ 25,000$ in taxable income last year.
Suppose the income tax rate is $10 \%$ for the first $\$ 8000$ plus $14 \%$ for the amount over $\$ 8000$.
How much must Susan pay in income tax for last year?

Step 1 ：Susan made \(\$ 25,000\) in taxable income last year.

Step 2 ：Suppose the income tax rate is \(10 \%\) for the first \(\$ 8000\) plus \(14 \%\) for the amount over \(\$ 8000\).

Step 3 ：To find out how much Susan must pay in income tax for last year, we need to calculate the tax for the first \(\$ 8000\) and the tax for the remaining amount over \(\$ 8000\). Then, we will add both tax amounts to get the total income tax.

Step 4 ：Tax for the first \(\$ 8000\) is \(8000 * 0.10 = \$ 800\).

Step 5 ：Tax for the remaining amount over \(\$ 8000\) is \((25000 - 8000) * 0.14 = \$ 2380\).

Step 6 ：Adding both tax amounts, we get the total income tax: \(800 + 2380 = \$ 3180\).

Step 7 ：\(\boxed{\$ 3180}\)