GRE General TestQuantitative ReasoningMedium
An architect is drawing a blueprint for a building. The scale of the blueprint is 1:50. If a wall on the blueprint measures 15 cm, what is the actual length of the wall in meters?
- A750
- B75
- C0.3
- D7.5
Show answer & explanationAnswer & explanation
Correct answer: D. 7.5
Multiply the blueprint measurement by the scale factor to get the actual length in centimeters. Then convert the actual length from centimeters to meters.
Why the other options are wrong
- A. This results from an incorrect conversion factor or miscalculation.
- B. This is the actual length in centimeters, not converted to meters.
- C. This results from dividing 15 by 50, then converting, which is incorrect.
Scale Factor and Unit Conversion
Using a given scale to convert a measurement from a model or drawing to its actual size, and then converting units if necessary.
- Scale factor 1:N means 1 unit on drawing = N units in real life.
- To find actual size, multiply drawing size by N.
- 1 meter = 100 centimeters.
Memory trick: Scale Up, Then Convert Down: Multiply by scale first, then divide for units.