Question

Question #95164

Answer 1

See below

Explanation:

a) Equations expressing how the fuel costs vary with the miles travelled:

Diesel:

`C_d=15m` where `C_d` is the cost of diesel and `m` is the # of miles.

Petrol:

`C_p=20m` where `C_p` is the cost of petrol and `m` is the # of miles.

b) Since the cost is in cents and assuming there are 100 cents to the euro, the equation would be:

`0.15m>=12000`

`m>= 80000` miles

There might be more to this one?

c) If the prices of both types of fuel fall by 25% that means:

Diesel:

`15(0.25)=3.75`

so the new price is:

`15-3.75=11.25` cents

OR

you can do the calculation in one shot by multiplying by `1-0.25` since it a percent decrease:

`15(1-0.25)=15(0.75)=11.25` cents

Petrol:

`20(0.75)=15` cents.

I hope this is of some help.