#### Explanation:

The easy way to do markup problems is just to multiply:

$270 xx 1.24 since you're adding 24%" of "270 = (0.24*270=64.8) and 270 (100% "of " 270) $\frac{24}{100} + \frac{100}{100} = \frac{124}{100} = 1.24$You can just simplify it to one step: $\rightarrow \text{ } 1.24 \times 270 = 334.80\$