Option B:
The 12th term is 354294.
Solution:
Given data:
and
To find
The given sequence is a geometric sequence.
The general term of the geometric sequence is .
If we have 2 terms of a geometric sequence and
(n > K),
then we can write the general term as .
Here we have and
.
So, n = 7 and k = 4 ( 7 > 4)
This can be written as
Taking cube root on both sides of the equation, we get
r = 3
Hence the 12th term of the geometric sequence is 354294.
Option D:
The approximate area of the figure is 109.6 square feet.
Solution:
The figure is splitted into three shapes.
One is rectangle and the other two is semi-circles.
Diameter of the semi-circle = 5 feet
Radius of the semi-circle = 5 ÷ 2 = 2.5 feet
Area of the semi-circle =
Area of the semi-circle = 9.8 square feet
Area of 2 semi-circles = 2 × 9.8
Area of 2 semi-circles = 19.6 square feet
Length of the rectangle = 18 feet
Width of the rectangle = 5 feet
Area of the rectangle = length × width
= 18 × 5
Area of the rectangle = 90 square feet
Area of the figure = Area of 2 semi-circles + Area of the rectangle
= 19.6 square feet + 90 square feet
= 109.6 square feet
The approximate area of the figure is 109.6 square feet.
Hence Option D is the correct answer.