The price of a sofa is \( \$ 300 \) before GST. How much did Sam pay after a \( 7 \% \) GST on the price of the sofa?

To calculate the total amount Sam paid after the \( 7\% \) GST, first find the GST amount by multiplying the sofa price by the GST rate: \[ \text{GST} = \$300 \times 0.07 = \$21 \] Now, add the GST to the original price of the sofa: \[ \text{Total Price} = \$300 + \$21 = \$321 \] So, Sam paid \( \$321 \) for the sofa after GST. One way to remember calculating GST is to think of it as simply multiplying the price by the percentage in decimal form and then adding that cost back to the original price. A common mistake is forgetting to change the percentage into a decimal format, which can throw off your calculations, so always double-check that it's \( 0.07 \) for \( 7\%\)!