Answer:
Option A. 55
Step-by-step explanation:
From the diagram given above, we discovered that the number of cubes in each stage is simply the addition of the squares of the number from 1 to the stage number i.e
1st Stage = 1² = 1 cube
2nd Stage = 1² + 2² = 1 + 4 = 5 cubes.
3rd Stage = 1² + 2² + 3² = 1 + 4 + 9
3rd stage = 14 cubes
With the above idea in mind, we can obtain the number of cubes in the 5th stage as illustrated below:
5th stage = 1² + 2² + 3² + 4² + 5²
5th stage = 1 + 4 + 9 + 16 + 25
5th stage = 55 cubes
Thus, there are 55 cubes in the 5th stage.
