A cyclist traveling 2km/h takes 15 minutes longer than his friend traveling at 32km/h. Calculate the distances covered

1 answer

To solve the problem, we can first convert the time difference of 15 minutes into hours, as the speeds are given in kilometers per hour (km/h).

15 minutes is equal to \( \frac{15}{60} = \frac{1}{4} \) hours.

Let \( d \) be the distance covered by both cyclists. We can set up equations based on the relationship between distance, speed, and time, which is given by the formula:

\[ \text{Time} = \frac{\text{Distance}}{\text{Speed}} \]

For the slower cyclist (2 km/h): \[ \text{Time}_{\text{slow}} = \frac{d}{2} \]

For the faster cyclist (32 km/h): \[ \text{Time}_{\text{fast}} = \frac{d}{32} \]

According to the problem, the time taken by the slower cyclist is 15 minutes longer than that taken by the faster cyclist. Thus, we can write the equation:

\[ \frac{d}{2} = \frac{d}{32} + \frac{1}{4} \]

Next, we need a common denominator to combine the fractions. The common denominator for 2 and 32 is 32. Thus, we can rewrite the equation:

\[ \frac{16d}{32} = \frac{d}{32} + \frac{1}{4} \]

Now, since \( \frac{1}{4} \) needs to be expressed with a denominator of 32, we have:

\[ \frac{1}{4} = \frac{8}{32} \]

Now substitute this back into the equation:

\[ \frac{16d}{32} = \frac{d}{32} + \frac{8}{32} \]

Next, multiply through by 32 to eliminate the denominator:

\[ 16d = d + 8 \]

Now, subtract \( d \) from both sides:

\[ 16d - d = 8 \] \[ 15d = 8 \]

Now, solve for \( d \):

\[ d = \frac{8}{15} \text{ km} \]

Now we can verify the time taken by both cyclists:

  1. Time taken by the slower cyclist:

\[ \text{Time}_{\text{slow}} = \frac{d}{2} = \frac{8/15}{2} = \frac{8}{30} = \frac{4}{15} \text{ hours} \]

  1. Time taken by the faster cyclist:

\[ \text{Time}_{\text{fast}} = \frac{d}{32} = \frac{8/15}{32} = \frac{8}{480} = \frac{1}{60} \text{ hours} \]

  1. Time difference calculation:

\[ \text{Difference} = \text{Time}{\text{slow}} - \text{Time}{\text{fast}} = \frac{4}{15} - \frac{1}{60} \]

To subtract these fractions, we need a common denominator. The least common multiple of 15 and 60 is 60. Thus:

\[ \frac{4}{15} = \frac{16}{60} \]

Therefore:

\[ \text{Difference} = \frac{16}{60} - \frac{1}{60} = \frac{15}{60} = \frac{1}{4} \text{ hours} = 15 \text{ minutes} \]

This confirms that our calculations are correct.

Thus, the distance covered by both cyclists is:

\[ \boxed{\frac{8}{15} \text{ km}} \]

Both cyclists travel the same distance of \( \frac{8}{15} \) km.