1.  The speed of a car increases by 2 kms after every one hour. If the distance travelled in the first one hour was 35 kms, what was the total distance travelled in 12 hours ?
A. 456 kms
B. 482 kms
C. 552 kms
D. 556 kms
E. None of these

Answer: Option C

Explanation:

Total distance travelled in 12 hours = (35 + 37 + 39 + ---- upto 12 terms).

This is an A.P :
First term, a = 35,
Number of terms, n = 12,
Common difference, d = 2.

∴ Required distance = 12/2 [2 x 35 + (12-1) x 2]
                             = 6 (70 + 22 )
                             = 552 km