A aluminum bar 4 feet long weighs 24 pounds. What is the weight of a similar bar that is 3 feet 3 inches long?

A. 29.54 LBS

B. 3 LBS

C. 19.50 LBS

D. 78 LBS

Respuesta :

Answer:

  C.  19.50 lbs

Step-by-step explanation:

3 feet 3 inches is nearly 4 feet, but is a little shorter. That means the weight of the bar will be nearly 24 pounds, but a little less.

It cannot be 29 or 78 pounds, because those weights are more than 24 pounds. It cannot be 3 pounds, because that weight is significantly less. The only viable answer choice is 19.50 pounds.

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We assume the weight is proportional to the length. Then the weight (w) of the shorter bar will be ...

  w/39 = 24/48 . . . . . weight in pounds/length in inches

  w = 39(24/48) = 39/2 = 19.5

The weight of the shorter bar is 19.5 pounds.