15. Five marks example problems VI

The distance $S$ (in kms) travelled by a particle in time '$t$' hours is given by $S(t) = \frac{t^2 + t}{2}$. Find the distance travelled by the particle after

 

(i) three and half hours.

 

 $kms$.

 

(ii) eight hours and fifteen minutes.

 

 $kms$.

 

[Note: Round off your answer to three decimal places.]