D.
This is because:
8/8 rounds up to a whole number and 12/9 and 3/2 are improper fractions as the numerator (top number) is more than the denominator (bottom number)
Answer: 9 inches.
Do the pythagorean theorem to find your answer.
Formula: a^2 + b^2 = c2
12 = b
15 = c
a^2 + 12^2 = 15^2
Simplify the equation
a^2 + 144 = 225
Subtract 144 on both sides.
a^2 = 81
Square root of 81 is 9.
This is a geometric sequence.
a = 15625,
Common ratio = 6250/15625 = 2500/6250 = 0.4
an for GP = ar^(n - 1)
= 15625*(0.4)^(n - 1)