edited by
3,470 views
7 votes
7 votes

An electric bus has onboard instruments that report the total electricity consumed since the start of the trip, as well as the total distance, covered. During a single day of operation, the bus travels on stretches M, N, O, and P, in that order. The cumulative distances travelled and the corresponding electricity consumption are shown in the Table below:$$\begin{array}{|l|l|}\hline \textbf{Stretch} & \textbf{Cumulative distance (km)} & \textbf{Electricity used (kWh)} \\\hline M & 20 & 12 \\\hline N & 45 & 25 \\\hline O & 75  & 45 \\\hline P & 100 & 57 \\\hline \end{array}$$

The stretch where the electricity consumption per km is minimum is

  1. $M$
  2. $N$
  3. $O$
  4. $P$ 
edited by

2 Answers

Best answer
15 votes
15 votes
Reaching point $M$ the bus traveled $20$ km and consumed $12$ units of electricity, So, electricity consumption per km$=\frac{12}{20}.$

From point $M$ to point $N$ distance traveled $=45-20=25,$ electricity consumed  $=25-12=13.$ So, electricity consumption per km $= \frac{13}{25}.$

Likewise at point $O,$ electricity consumption per km$=\frac{20}{30}$ and at point $P$ it is $\frac{12}{25}.$ So, least electricity consumption per km is at point $P.$

Answer is D
edited by
7 votes
7 votes
Electricity used is also cumulative as it is mentioned in the question -- "corresponding electricity consumption"

M - 12/20

N -  13/25

O - 20/30

P - 12/25.

So, P is the stretch with minimum consumption per km.
edited by
Answer:

Related questions

9 votes
9 votes
4 answers
1
16 votes
16 votes
1 answer
2
Akash Kanase asked Feb 12, 2016
2,199 views
if $a^2+b^2+c^2=1$ then $ab+bc+ac$ lies in the interval$[1,2/3]$$[-1/2,1]$$[-1,1/2]$$[2,-4]$
11 votes
11 votes
3 answers
3
0 votes
0 votes
1 answer
4
Akash Kanase asked Feb 12, 2016
6,275 views
Ram and Ramesh appeared in an interview for two vacancies in the same department. The probability of Ram’s selection is $1/6$ and that of Ramesh is $1/8$. What is the p...