The speed of a car increases by 2 kms after every one hours. If the distance travelled in the first one hour was 35 kms, what was the total distance travelled in 12 hours ?

Solution (By Examveda Team)

Total distance travelled in 12 hours
= (35 + 37 + 39 +...... upto 12 terms)
This is an A.P. with first term, a = 35,
Number of terms, n = 12,
Common difference, d = 2
∴ Required distance :
$$\eqalign{ & = \frac{{12}}{2}\left[ {2 \times 35 + \left( {12 - 1} \right) \times 2} \right] \cr & = 6\left( {70 + 22} \right) \cr & = 552{\text{ km}} \cr} $$