To entertain the crowd a clown rode a tricycle in the race.His race can be modeled by the fuction f(x)=20-x .Without graphing or making a table fully discribe the clown's ride.

We are given function for total distance remaining after x number of minutes f(x)=20-x, where x is taken for per unit time of ride.
For 1 unit of time the distance would remain 20-1=19 units.
The clown rode with the same rate. In 2 unit of time the distance remain 20-2 =18 units, in 3 units of time, the distance remain 20-3=17 units. After 20 units of time the total distance would remain 20-20= 0 unit. Therefore, after 20 units of time the race finished.