WholeLottaLove wrote:
Half an hour after car A started traveling from Newtown to Oldtown, a distance of 62 miles, car B started traveling along the same road from Oldtown to Newtown. The cars each met each other on the road 15 minutes after car B started it's trip. If Car A traveled at a constant rate that was 8 MPH greater than car B's constant rate, how many miles had car B driven when they met?
A) 14
B) 12
C) 10
D) 9
E) 8
You're suposed to convert the hours into fractions (i.e. Car A traveled for .75 hours and Car B traveled for .25 hours) but why can't I solve just using minutes (i.e. 45 and 15 minutes respectively)?
Thanks!
Using FractionsFirst case:-
Car A started first and travelled for half an hour.
Distance travelled by car A = 0.5A (A and B are the speeds of the respective cars)
Second case:-
Next They travel for 15 min and meet each other on the road.
During this time
Distance travelled by car A = 0.25 A
Distance travelled by car B = 0.25B
Now summing all the distances wee should get 62 miles
So 0.25A + 0.25B + 0.5A = 62
But A = B+8
So we will get A as 64 and B as 56. So distance travelled by car B = 56 *0.25 = 14
In Minutes.First case:- Distance travelled by car A = 30 * A (A is in miles per minute)
Second Case
Distance travelled by A = 15*A
Distance travelled by B = 15*B
So total distance travelled = 62 = 15*A + 15*B + 30*A
=> 62 = 45A + 15B
= 15(3A + B)
But A = B + 8/60(miles/minute)
So 62 = 15(4B + 2/5)
=> 62 = 6 + 4(15B)
=> 15B = 14.
Now distance travelled by Car B = 15 * B
So answer is 14