Abox has dimensions of 14 inches long, 1.5 feet wide, and 7 inches high. what is the volume of the box? the formula for the volume is v = l ⋅ w ⋅ h.
a.1.02 cubic inches (in3)
b. 12.25 cubic inches (in3)
c.147 cubic inches (in3)
d. 1764 cubic inches (in3)

C is the answer
Just do 14 x 1.5 x 7= 147

You have inches and feet.
You need to convert the 1.5 feet to inches, to do that you need to know how inches are in a foot. 

(1 foot = 12 inches)

Now, since you have 1.5 feet, it will be 18 inches.
(1 foot is 12 and .5 is 6. 12 + 6 =18)

Now you can multiply everything together. (14*18*7 = 1764 cubic inches.)

Your final answer would be D.