Highway to Hell!

I go with D 36.

Gallons used in city = 10/25
Gallons used on Highway= 50/40

Total distance travelled= 10+50 = 60 miles

So average fuel used while covering these miles = Distance/Total fuel used
= (60)/(10/25 +50/40) = 36 approx.


Should Be D.

The answer is B

In the city 25 miles per gallon . Hence when it travles 10 miles , it uses 10/25 gallons.

Similarly on the highway it uses 5/4 gallons .

Now total gallons consumed is sum of the above which is 1.65 gallons . total distance travelled is 60 miles . Hence the average is 60/1.65 which is approximately 30 miles .

Let me know if I am incorrect.

Silly mistake guys . the answer is 36.

malolakrupa
60/1.65 = 36.36.. i think u missed there...

Basically, this question asks if you know how to find "average speed".
Average speed = total distance / total time

city speed is 25
and total distance the city speed will go is 25 miles per gallon.<----this is the rate, amigo.

so don't forget the formula, distance= rate * time

10 = 25 t
t=2/5

then the rest 50 miles with 40 rate.
50= 40 t
t = 5/4

and then follow the formula.
total distance is 10 + 50 = 60 miles

average speed is 60 divided by total distance (2/5 + 5/4)


then you will get 36.3xxxxx

so the closest one is D, 36.



hope this helps.