Car

[Maratha1]

A certain car averages 25 miles per gallon of gasoline when driven in the city and 40 miles per gallon when driven on the highway. According to these rates the following is the closest to the number of miles per gallon that the car averages when it is driven at 10 miles in the city and then 50 miles on the highway?
1)28
2)30
3)33
4)36
5)38

I found similar problem on the forum but wasnt quite convinced with the answer. Can anyone please shed some light on this again?

[cramya]

City

25 miles 1 gallon
10miles ?

1/25*10 = 2/5 gallons

Highway:

40 miles 1 gallon
50

1/40*50 = 5/4 gallons used


Total miles drive = 50+10
Total gallons used = 2/5+5/4 = 33/20

33/20 gallons 60 miles
1 gallon ?

60*20/33 =~= 36 gallons

Hope this helps!

Regards,
CR

[4meonly]

When I 1st encountered Rate/distance/time questions i was not able to solve them.
I would recommend those who have similar problems to write down the mail formula:
Distance = speed * time
And use it everu time you see this type of questions.

This helped me very much.

[bmlaud]

60 miles / (33/20) gallons = 36.3 ~ 36.... D

[Maratha1]

You gys ar amazing! THank you very much Cramya