Question

The speed of a car is increased by $2$ km after every hour. If the distance traveled in the first hour was $35$ km, what was the total distance traveled in $12$ hours ?

• A. $522$ km
• B. $456$ km
• C. $556$ km
• D. $482$ km
• E. $552$ km
• F. None of the above

Answer 1

The correct option is E $552$ km

$A$.............$35$ kmph.............$37$ kmph..............$55$ kmph...........$57$ kmph...........$B$
Speed increase in AP.
Common difference $\left(d\right)=2$
Number of term $=12$
First term $\left(a\right)=35$
${12}^{th}$ term $=a+11d=35+2\times 11=37$
Sum $=$ (No. of terms/2) $\times$ (first term $+$ last term)
Sum $=\left(\frac{12}{2}\right)\times (35+57)=552$
Total distance traveled $=552$ km.