The speed of a car increases by 2 kms after every one hour. If the distance travelling in the first one hour was 45 kms. what was the total distance traveled in 12 hours? Choose the correct choice from the following choices:
A) 252 kms  B) 152 kms  C) 672 kms  D) 752 kms  E) 152 kms

Rationale: explanation : total distance travelled in 12 hours = ( 45 + 47 + 49 + . . . . . upto 12 terms ) this is an a . p with first term , a = 45 , number of terms , n = 12 , d = 2 . required distance = 12 / 2 [ 2 x 45 + { 12 - 1 ) x 2 ] = 6 ( 112 ) = 672 kms . answer : c
Answer: C