If an elastic is stretched by 86% to a length of 5.8 m, what is its original length?

To calculate the original length of the elastic before it was stretched, it's important to first understand that "stretched by 86%" means that the stretch is 86% of the original length.

Let the original length be represented as ( L ). If the elastic is stretched by 86%, that means it is now at a length of ( L + 0.86L ), which simplifies to ( 1.86L ). According to the problem, this stretched length equals 5.8 m. Therefore, we can set up the equation:

( 1.86L = 5.8 )

To solve for ( L ), divide both sides by 1.86:

( L = \frac{5.8}{1.86} )

Calculating that gives:

( L ≈ 3.118 m )

Thus, the original length of the elastic before it was stretched to 5.8 m is approximately 3.118 m. This confirms that option A is accurate based on the understanding of how percentages of original lengths work in relation to stretching objects.