The time it takes John to get to the store is inversely proportional to his rate. John walks at a rate of 3 miles per hour. It takes him 20 minutes to walk to the store. He rides his bike at a rate of 15 miles per hour. How long would it take John to ride his bike to the store?

Question

4 min
100 min
8 min
2.25 min

Answer 1

We can set up an inverse proportion equation to solve for the time it would take John to ride his bike to the store:

rate * time = constant

For walking, we have:

3 mph * 20 min = constant

To find the constant, we convert the time to hours:

20 min = 20/60 hours = 1/3 hours

Now we can solve for the constant:

3 mph * 1/3 hours = constant
1 mph = constant

Now we can use the constant to find the time it would take John to ride his bike:

15 mph * time = 1 mph

Simplifying the equation:

time = 1/15 hours

Converting the time to minutes:

1/15 hours * 60 min/hour = 4 min

Therefore, it would take John 4 minutes to ride his bike to the store.