It takes the high-speed train x hours to travel the z miles from Town A to Town B at a constant rate, while it takes the regular train y hours to travel the same distance at a constant rate. If the high-speed train leaves Town A for Town B at the same time that the regular train leaves Town B for Town A, how many more miles will the high-speed train have traveled than the regular train when the two trains pass each other?
z(y – x)/x + y
z(x – y)/x + y
z(x + y)/y – x
xy(x – y)/x + y
xy(y – x)/x + y
time speed n distance...pls help
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Lets assume that they meet at distance P from Town B
Normal Train..Starts from Town B
Distance Z in Y hrs
Distance P in (YP/Z) hrs
High Speed train..Start from Town A
Distance Z in X hrs
Distance Z-P in [(Z-P)X/Z] hrs
Now,
Time it takes the Normal train to cover distance P = Time it takes the Normal train to cover distance Z-P
So, (YP/Z) = [(Z-P)X/Z]
=> P= XZ/X+Y..............I
So, Z-P = YZ/X+Y.........II
Substracting I from II gives us the result
{Z(Y-X)}/(X+Y)
I think A is the correct answer.
Normal Train..Starts from Town B
Distance Z in Y hrs
Distance P in (YP/Z) hrs
High Speed train..Start from Town A
Distance Z in X hrs
Distance Z-P in [(Z-P)X/Z] hrs
Now,
Time it takes the Normal train to cover distance P = Time it takes the Normal train to cover distance Z-P
So, (YP/Z) = [(Z-P)X/Z]
=> P= XZ/X+Y..............I
So, Z-P = YZ/X+Y.........II
Substracting I from II gives us the result
{Z(Y-X)}/(X+Y)
I think A is the correct answer.
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- Junior | Next Rank: 30 Posts
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Correct ANswer is "A"
Take any pt. b/w A & B.
Lets say high-speed train travel z-d distance, and low speed train travels d distance before they meet (time takes is same).
Extra mils travelled by high speed train is (z-d)-d i.e z-2d we hav to find out:
So we have two equation:
(z-d) = z/x * t
d = z/y * t
you can find var "d" from above, to be 2xz/(x+y)
Thus z-2d = z(y-x)/(x+y)...choice "A"
Hope it help you ppl.
Take any pt. b/w A & B.
Lets say high-speed train travel z-d distance, and low speed train travels d distance before they meet (time takes is same).
Extra mils travelled by high speed train is (z-d)-d i.e z-2d we hav to find out:
So we have two equation:
(z-d) = z/x * t
d = z/y * t
you can find var "d" from above, to be 2xz/(x+y)
Thus z-2d = z(y-x)/(x+y)...choice "A"
Hope it help you ppl.