Given that,
Speed of first bicycle = 9 mph
Speed of second bicycle = 5 mph
Suppose the length of the circle 24 miles.
We need to find the relative velocity
Using formula of relative velocity
![v=v_(1)-v_(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/xjzhh5lz7xrejt3egitp7ka0h275k2t8ni.png)
Put the value into the formula
![v=9-5](https://img.qammunity.org/2021/formulas/mathematics/high-school/k07f1pbr5gutej3dqdx6h1eoxhj398ygc0.png)
![v=4\ mph](https://img.qammunity.org/2021/formulas/physics/college/ubdq9du5av7u713zqfzp2sd08tj2kvy5d9.png)
We need to calculate the time
Using formula of time
![t=(d)/(v)](https://img.qammunity.org/2021/formulas/physics/college/cwq2qxh5njqmlzqcaa110w0i173l35zgms.png)
![t=(24)/(4)](https://img.qammunity.org/2021/formulas/mathematics/high-school/cfyekijdi4j1vxapf4s84mxcggfs9t4zfd.png)
![t=6\ hr](https://img.qammunity.org/2021/formulas/mathematics/high-school/dqqjrtx2y3hf6mrxw56p63i7qxes9g1du7.png)
We need to calculate the distance of the points where the two bicycles meet
Using formula of distance
For first bicycles,
![d=9*6](https://img.qammunity.org/2021/formulas/mathematics/high-school/5q3h1uz76gkvutghc2ol8fthe0f5yl6mcn.png)
![d=54\ miles](https://img.qammunity.org/2021/formulas/mathematics/high-school/3z20nrlc44ihv9w0vv9jfhfvb6hn24qdrh.png)
For second bicycles,
![d'=5*6](https://img.qammunity.org/2021/formulas/mathematics/high-school/e3nlx95f07grc34z69y21wslfz3abiw9g0.png)
![d'=30\ miles](https://img.qammunity.org/2021/formulas/mathematics/high-school/hujmcx82t1upth5lzmoqesufo04s819vpe.png)
Hence, The points where the two bicycles meet after every 6hr at 30 miles and 54 miles.