Respuesta :

Answer: 13 [tex]\frac{1}{3}[/tex] pounds

Step-by-step explanation:

     We will set up a proportion. I will have the weight, in pounds, on the top (numerator) and the length, in inches, on the bottom (denominator).

[tex]\frac{12}{36} =\frac{x}{40}[/tex]

     Cross-multiply:

36 * x = 12 * 40

36x = 480

     Divide both sides of the equation by 36:

x = 13 [tex]\frac{1}{3}[/tex] pounds

Answer:

Step-by-step explanation:

First find unit weight.

1 foot = 12 inches

3 ft = 3*12 = 36 inches

3ft 4 inches = 36 + 4 = 40inches

Weight of 36 inches  long bar =   12  pounds

Weight of 1 inch bar = 12/36

[tex]\text{Weight of 40 inches long bar = $\dfrac{12}{36}*40$}[/tex]

                                             = 13.3 pounds