Bunuel wrote:

Starting from her home, Mirinda rides her bike in a straight line due south for 24 kilometers, then turns and rides in a straight line due west for 7 kilometers, at which point she stops. Assuming that she can ride in any direction with no barriers, what is the distance of her shortest route back home?

A. 20 kilometers

B. 22 kilometers

C. 25 kilometers

D. 28 kilometers

E. 31 kilometers

Miranda has created the legs of a right triangle whose hypotenuse is her shortest route back home.

This problem takes just seconds if you catch 7-24-25; it is a Pythagorean triplet.

\(7^2 + 24^2 = 25^2\)

\(49 + 576 = 625\)

Knowing what most sources list as the top four Pythagorean triplets can save a lot of time. They are 3-4-5, 5-12-13, 7-24-25, and 8-15-17

See, e.g.,

Bunuel Right TriangleAnswer C

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