JEE MATHEMATICS MCQ: RATE MEASURE

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The cost of running a bus from

\mathrm{A}

\mathrm{B}

, is

₹\left(a v+\frac{b}{v}\right)

, where

v \mathrm{~km} / \mathrm{h}

is the average speed of the bus. When the bus travels at

30 \mathrm{~km} / \mathrm{h}

, the cost comes out to be

₹ 75

while at

40 \mathrm{~km} / \mathrm{h}

, it is

₹ 65

. Then the most economical speed(in

\mathrm{km} / \mathrm{h}

) of the bus is :

View answer and explanation

Correct option: C

Option C (60) is correct because it represents the speed at which the cost function is minimized, found by taking the derivative and setting it to zero.

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