Answer
See below:
Work Step by Step
(a)
In order to calculate FICA taxes, multiply wages with the tax rate.
\[\begin{align}
& \text{FICA}\,\text{taxes}=\text{Wages}\times \text{Tax}\,\text{rate} \\
& =\$18,000\times5.65\text{percent}\\&=\$18,000\times0.0565\\&=\$1,017\end{align}\]
(b)
In order to calculate income tax, first calculate taxable income by deducting the sum of exemptions and deductions from adjusted gross income.
\[\begin{align}
& \text{Taxable}\,\text{income}=\text{Adjusted}\,\text{gross}\,\text{income}-\left( \text{Exemptions}+\text{Deductions} \right) \\
& =\$18,000-\left(\$3,800+\$5,950\right)\\&=\$18,000-\$9,750\\&=\$8,250\end{align}\]
Now, calculate income tax by multiplying $8,700 with 10% tax rate
\[\begin{align}
& \text{Income}\,\text{tax}=10\text{percent}\times \$8,250\\&=0.10\times\$8,250\\&=\$825\end{align}\]
(c)
In order to calculate the percent of federal taxes, divide the sum of FICA taxes and income tax with gross income and multiply by 100.
\[\begin{align}
& \text{Percent}\,\text{federal}\,\text{taxes}=\frac{\text{FICA}\,\text{taxes}+\text{Income}\,\text{tax}}{\text{Gross}\,\text{income}} \\
& =\frac{\$1,017+\$825}{\$18,000}\\&=\frac{\$1842}{\$18,000}\\&=0.1023\end{align}\]
\[\begin{align}
& =0.1023\times 100 \\
& =10.23\approx 10.2\text{percent} \\
\end{align}\]
