Leah walked 4/5 of a mile in 3/8 of an hour.

What was Leah’s walking speed in miles per hour?

Responses
A 12/40 mph






B 12/32 mph






C 1 13/15 mph






D 2 2/15 mph

1 answer

To find Leah's walking speed in miles per hour, we need to divide the distance she walked by the time it took her to walk that distance.

Leah walked \( \frac{4}{5} \) of a mile in \( \frac{3}{8} \) of an hour.

Her walking speed \( S \) in miles per hour is given by:

\[ S = \frac{\text{Distance}}{\text{Time}} = \frac{\frac{4}{5}}{\frac{3}{8}} \]

To divide by a fraction, we multiply by its reciprocal:

\[ S = \frac{4}{5} \times \frac{8}{3} \]

Now, we can multiply the fractions:

\[ S = \frac{4 \times 8}{5 \times 3} = \frac{32}{15} \]

Now we can convert \( \frac{32}{15} \) into a mixed number:

  • Divide 32 by 15. \( 32 \div 15 = 2 \) with a remainder of 2.
  • Thus, we can write this as \( 2 \frac{2}{15} \).

Therefore, Leah’s walking speed is:

\[ \boxed{2 \frac{2}{15}} \text{ mph} \]

The correct answer is option D: \( 2 \frac{2}{15} \) mph.