648 cm
To find the volume of a rectangular prism (such as the one in the picture) you would do:
V=L*W*H
So plugging the numbers in:
V=18*12*3
15% of 40
Of = Multiplication
15% Multiply by 40
Set up a equation
15/100= x/140
Cross Multiply
15* 140= 100*x
2100= 100x
Divide both sides by 100x
2100/100x= 100x/100x
X= 21
Answer:
Option C)
for
is not the correct way to define the given infinite sequence

Step-by-step explanation:
Given infinite sequence is 
Option B)
for
is not the correct way to define the given infinite sequence 
Now verify
for
is true for the given infinite sequence
That is put n=1,2,3,.. in the above function

When n=1, 


When n=2, 


When n=3, 


and so on.
Therfore
for
is not the correct way to define the given infinite sequence

Therefore option C) is correct