Need to cross a bridge...

Another homework problem... :(

Andrea, Bill and Charlotte need to cross a bridge as quickly as possible.

Andrea can walk across in 10 minutes, Bill walks it in 5 minutes and Charlotte walks it in 2 minutes. There is also a bicycle available which can thake any one person across the bridge in one minute. It cannot take more than one person at a time.

Explain how it is possible for the trioto cross the bridge in 3 minutes or less. Give distances [fractions of the length of the bridge] and/or times travelled on foot and on bicycle for each person.

Please include:

- A correct distance for one person to ride the bicycle

- A correct distance for another to ride the bicycle

- A correct description of how it is done.

Thankyou for reading and hope you can help. :)