operations on rational numbers

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operations on rational numbers

by pullagurla » Thu Sep 02, 2010 10:43 pm
Car A is 20 miles behind Car B, which is traveling in
the same direction along the same route as Car A.
Car A is traveling at a constant speed of 58 miles
per hour and Car B is traveling at a constant speed
of 50 miles per hour. How many hours will it take for
Car A to overtake and drive 8 miles ahead of Car B ?
(A) 1.5
(B) 2.0
(C) 2.5
(D) 3.0
(E) 3.5

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by Rahul@gurome » Thu Sep 02, 2010 11:27 pm
Solution:
Car A needs to cover (20 + 8) or 28 miles more than B.
Their relative speed is 58 - 50 = 8 miles per hour.
So the required time is 28/8 or 3.5 hrs.

The correct answer is (E).
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