Hi Ramesh

glad you are using our data for your learning process.

if you know
a: the how long the whole scan takes
and
b: the time of repetition (TR),
the number of time points will be
a/b.

In fact, you don't have to calculate this if you have data in hand. The fMRI data usually will have this information saved in the file header. If you use AFNI, you can use the command `3dinfo` to see it. If you use FSL, you can use `fslinfo` or `fslhd`

Have fun!

Yang