Question

Question 58
Fill in the blank to make the statement true.
Identical cubes are stacked in the corner of a room as shown below. The number of cubes that are not visible are ___.

Answer 1

20
The number of cubes that are not visible are 20.
first row = 10 cubes are not visible
second row = 6 cubes are not visible
third row = 3 cubes are note visible
fourth row = 1 cube is not visible
hence, 10+6+3+1 = 20