On moving day, Guyton needs to rent a truck. The length of the cargo space is 10 ft , and the height is 1 ft less than the width. The brochure indicates that the truck can hold 420 ft3 . What are the dimensions of the cargo space? Assume that the cargo space is rectangular shape.
Answer:
The dimensions; width w is 7 ft and height is 6 ft
Step-by-step explanation:
L = 10 ft the length of the cargo space
w = the width of the cargo space
h = the height of the cargo space the height is 1 ft less than the width
h = w - 1
The truck can hold 420 ft^3 - this means the volume of the space V = 420 ft^3
But V = L*w*h
Substitute h = w - 1 into the Volume equation
Therefore,
10*w*(w - 1) = 420
10w^2 - 10w - 420 = 0
By Using quadratic equation formula to solve and considering positive answer,
w = {-b +- √(b^2 - 4ac)}/2a
Where;
a = 10, b = -10 and c = -420
w = {-(-10) +- √(-10^2 - 4(10)(-420)}/2(10)
w = {-(-10) +- 130}/20
w = (10 + 130)/20 = 140/20 = 7
Or
w = (10 -130)/20 = -120/20 = -6
Here,
I take positive answers and the width is 7 ft
Also, from h = w - 1
height = 7 - 1 = 6 ft