Question

Bilal has decided to buy a car. He has to choose between a diesel car and a petrol car. The diesel car
costs Dhs12000 more than the petrol car. However, it can travel 13 kilometres per litre, whereas the
petrol car can only travel 10 kilometres per litre. Also, diesel costs Dhs41.60 per litre, and petrol costs
Dhs52.00 per litre. If he buys a diesel car, how far must he drive before the savings in fuel covers the
extra price of the diesel car?

Answer 1

Cost exess of deisal car =12000
mielage of deisal car =13
mielage of petrol car =10
cost of deisal =41. 6
cost of petrol =52

let x be the distance he should cover the cos t

money to be spend for petrol car to cover the distance x= (x/10)*52

money to be spend for deisel car to cover the diatance x= (x/13)*41.6

the difference of this cost should be equal to the extra cash spend on deisel car =12000


so
12000={(x/10)*52}-{(x/13)*41.6}
=(52x/10)-(41.6x/13)
=2x
so x =12000/2
=6000km

so he has to cover 6000 km