8051 timer and counter

hi everybody. i have a question about 8051. timer and counter must work same time at the code.

an encoder at the car wheel produce 256 pulse for one tour. one tour is one meter. what is the speed finds assembly code?

mov tmod,#00100010
???
i know this question easy for you. thank you

How much do you know about the problem ?

Are you given the count per second ?
Are you supposed to display a result ?