The speed of a car increases by 2 kms after every one hour. If the distance travelled in the first one hour… · ABC26GN3633
Subject: General Aptitude · Chapter: Time and Distance
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
Answer (as printed): C
Explanation
Total distance travelled in 12 hours $=(35+37+39+\ldots$ upto 12 terms$)$. This is an A.P. with first term $a=35$, number of terms $n=12$, common difference $d=2$. $$\therefore \text{Required distance} = \frac{12}{2}[2 \times 35+(12-1) \times 2] = 6(70+22) = 552 \text{ km}.$$
Explanation as extracted from the printed page; notation may be imperfect.