Final answer:
To find the real-life size of a deck on a landscaping plan drawn on a 1:50 scale, where the deck measures 12cm by 10cm on the plan, you multiply each dimension by 50, yielding dimensions of 600cm by 500cm, option A).
Step-by-step explanation:
The question involves a landscaping plan that is drawn on a 1:50 scale, asking how large a deck is in real life if it measures 12cm by 10cm on the plan. To calculate the actual size of the deck, you multiply the dimensions on the drawing by the scale factor. Since the scale is 1:50, every 1 cm on the plan corresponds to 50 cm in real life.
For the length: 12 cm × 50 = 600 cm.
For the width: 10 cm × 50 = 500 cm.
Therefore, the actual size of the deck in real life is 600 cm by 500 cm, which corresponds to option A).