Geometry Practice : Measurement

This aptitude practice question is a counting method question in geometry.

Question

A stairway 10ft high is such that each step accounts for half a foot upward and one-foot forward. What distance will an ant travel if it starts from ground level to reach the top of the stairway?

1. 30 ft
2. 33 ft
3. 10 ft
4. 29 ft

  Correct Answer      Choice (4). The ant travels 29 ft.

Explanatory Answer

The ant moves 20 times upward (vertically) and only 19 times forward (horizontally).

Therefore, the ant covers a distance of 20 * 0.5 = 10 feet when it moves upwards.
And moves 19 * 1 = 19 feet forward.

The total distance covered by the ant = 29 ft.

  The correct answer is Choice (4).