Solve $40 \%$ of 75 is what number?

Step 1 ：Translate the problem into a mathematical expression: 40% of 75 is what number? This can be written as \(0.40 \times 75 = x\).

Step 2 ：Calculate the value of \(x\) using the formula \(x = \frac{percentage}{100} \times number\).

Step 3 ：Substitute the given values into the formula: \(x = \frac{40}{100} \times 75\).

Step 4 ：Calculate the value of \(x\): \(x = 30\).

Step 5 ：Final Answer: \(\boxed{30}\).