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?

Question: 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:
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
d = 2

Required distance = (12/2){(2 × 35) + (12 - 1) × 2}
= 6 × (70 + 22)
= 552 kms.