A mouse traveled a total distance of StartFraction 3 Over 24 EndFraction of a mile in a maze over the past 3 hours. The mouse traveled the same distance each hour. To determine the distance that the mouse traveled each hour, Matt performed the calculations below.

StartFraction 3 Over 24 EndFraction divided by 3 = StartFraction 3 Over (24 divided by 3) EndFraction = StartFraction 3 Over 8 EndFraction
He concluded that the mouse traveled StartFraction 3 Over 8 EndFraction of a mile each hour. What is Matt’s error?
Matt should have multiplied mc012-4.jpg by 24 instead of dividing it by 3.
Matt should have multiplied mc012-5.jpg by 3 instead of dividing it by 3.
Matt should have divided the numerator but not the denominator of mc012-6.jpg by 3.
Matt should have divided the numerator and denominator of mc012-7.jpg by 3.

1 answer

Let's analyze the situation step by step.

The mouse traveled a total distance of \( \frac{3}{24} \) of a mile in 3 hours. To find the distance the mouse traveled each hour, we need to divide the total distance by the total time:

\[ \text{Distance per hour} = \frac{\text{Total distance}}{\text{Total time}} = \frac{\frac{3}{24}}{3} \]

Matt's calculation shows:

\[ \frac{3}{24} \div 3 = \frac{3}{(24 \div 3)} = \frac{3}{8} \]

This calculation is incorrect because to divide a fraction by a whole number, we multiply the denominator by that whole number, not divide it:

\[ \frac{3}{24} \div 3 = \frac{3}{24} \times \frac{1}{3} = \frac{3 \cdot 1}{24 \cdot 3} = \frac{3}{72} \]

Now, simplifying \( \frac{3}{72} \):

\[ \frac{3}{72} = \frac{1}{24} \]

So the mouse traveled \( \frac{1}{24} \) of a mile each hour.

Looking at Matt’s conclusion, he incorrectly concluded that the distance per hour was \( \frac{3}{8} \) of a mile instead of \( \frac{1}{24} \) of a mile.

Now, let’s match the reasoning to the possible errors listed:

  • Matt's error correctly relates to how he divided the total distance. He should have multiplied by the reciprocal of the 3, not divided.

Thus, the correct option is:

Matt should have multiplied \( \frac{3}{24} \) by 3 instead of dividing it by 3.