Indian Institute of Foreign Trade 2009 Solved Paper

SUV consumes diesel at the rate of

1

400

(

100

x

+x) liters per km
Cost of 1 liter diesel is Rs. 35
Total distance to be covered is 800 kms
Therefore total cost of diesel consumption by SUV is

1

400

(

100

x

+x)×35×800
Per hour Chargers of Driver is Rs. 125 and total time is

800

x

Therefore total cost of driver is

100000

x

Total Cost =

100000

x

+

1

400

(

100

x

+x)×35×800
=

10700

x

+70x
We need total cost to be minimum so differentiating total cost w.r.t x and equating to 0 we get
0=−

107000

x2

+70
i.e, x2=

107000

70

x = 12 approximately
Therefore option 'A' is the answer