Answer: A
Explanation:
The first square is 22 inches on a side.
The second is 17.6 inches on a side
the third is 14.08 inches on a side.
We can suppose that we have a constant rate of decrease betwen the sides cubes, this means that:
22in*x = 17.6in
where x is the rate of scale.
x = 17.6/22 = 0.8
Now we test this with the second and third:
17.6in*0.8 = 14.08in
Ok, this works.
then the side of n-th cube can be found with the equation
L = 22*0.8^(n-1)
we can try the different options and see which one gives a value smaller than 10.
A) n = 5
L = 22*0.8^4 = 9.01
Then the correct option is A