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A cat and a dog have a race. The cat’s strides are 30% shorter than the dog’s but it makes 30% more strides than the dog. Which of them will win the race?

Respuesta :

Let [tex]x[/tex] be the length of a cat's stride, and [tex]y[/tex] their stride per time unit ratio.

So, in a time unit, the cat will cover a distance of [tex]xy[/tex]

Dogs strides are 30% longer, do a dog's stride is

[tex]\dfrac{130}{100}x = \dfrac{13x}{10}[/tex]

But its stride per time unit is 30% less:

[tex]\dfrac{70}{100}y = \dfrac{7y}{10}[/tex]

So, in a unit of time, the dog will cover a distance of

[tex]\dfrac{13x}{10}\dfrac{7y}{10} = \dfrac{91}{100}xy[/tex]

So, in the same amount of time, the dog covers 91% of the distance of the cat.

Assuming the strides take the same amount of time, the dog wins.

1.30 · 0.70 = 0.91