Question

How many cubes are needed to make this interesting model?
• Here are some drawings of the model. Mark the correct top view drawing with 'T' and the correct side view drawing with 'S'.





(a)

(b)

(c)





(d)

Answer 1

Number of cubes in the top layer = 4 + 5 = 9
Number of cubes in the second layer from top = 4 + 5 + 3 + 4 = 16
Number of cubes in the third layer from top = 4 + 5 + 3 + 4 + 2 + 3 = 21
Number of cubes in the fourth layer from top = 4 + 5 + 3 + 4 + 2 + 3 + 2 + 1 = 24
Number of cubes in the bottom layer = 4 + 5 + 3 + 4 + 2 + 3 + 2 + 1 + 1 = 25

Total number of cubes in the model = 9 + 16 + 21 + 24 + 25 = 95

The correct drawing for the top and side view is given below:



T , S