The speed of a car increases by 2 kms after every one hour. If the distance travelling in the first one hour was 55 kms. what was the total distance travelled in 12 hours?	Pick one.
A) 252 kms
B) 152 kms
C) 552 kms
D) 792 kms
E) 152 kms

Rationale: "explanation : total distance travelled in 12 hours = ( 55 + 57 + 59 + . . . . . upto 12 terms ) this is an a . p with first term , a = 55 , number of terms , n = 12 , d = 2 . required distance = 12 / 2 [ 2 x 55 + { 12 - 1 ) x 2 ] = 6 ( 132 ) = 792 kms . answer : d"
Answer: D