Question

The speed of a locomotive without any wagons
attached to it is 40 kmph. It diminishes by a quantity
which is proportional to the cube root of the number
of wagons attached. If the speed of the locomotive is
34 kmph when 27 wagons are attached, what is the
maximum number of wagons that can be attached if
the condition is that the speed should not fall below
30 kmph?
(A) 64 (B) 125 (C) 216 (D) 343​

Answer 1

Answer:

Step-by-step explanation:

speed= k*cube root of (wagons)+c --------1

If the speed of the locomotive is  34 kmph when 27 wagons are attached,

34=k*cube root of 27+c -----------2

The speed of a locomotive without any wagons  attached to it is 40 kmph.

40=k*cube root of 0+c---------3

hence, c=40 then put in 2

34=3k+40

k=-2

if speed = 30

from 1

speed = -2*cube root of wagons+40

wagons = [(40-speed)/2]^3

wagons = [(40-30 )/2]^3

wagons = 125