Question

It costs Rs. $10$/kilometer to fly and Rs. $2$/kilometer to drive. If one travels $200$ km covering $x$ km of the distance by flying and the rest by driving, then the cost of the trip is

• A. Rs. $2,000$
• B. Rs. $24,000$
• C. Rs.$(8x+400)$
• D. Rs. $(12x+400)$

Answer 1

Answer: (C)

Rs.$(8x+400)$

Let distance travelled by flying is $x$ km.
Hence, the distance travelled by driving $=(200-x)$km.
The cost of flying $=$ Rs. $10$ per km
Hence, the cost of flying $x$ km $=10\times x=10x$
The cost of driving $=$ Rs. $2$ per km
The cost of driving $(200-x)$ km $=2\times (200-x)=400-2x$
Hence, the total cost $=10x+400-2x=$Rs.$8x+400$