an ant on walk

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an ant on walk

by sanju09 » Fri Feb 27, 2009 6:14 am
A stairway 10 ft high is such that each step accounts for half a foot upward and one-foot forward. What distance will an ant travel if it starts from ground level to reach the top of the stairway?

(A) 30 ft
(B) 33 ft
(C) 10 ft
(D) 29 ft
(E) 20 ft

OA D
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by DanaJ » Fri Feb 27, 2009 6:54 am
You've got a 10 ft high staircase, made of 20 stairs (10: 1/2 ft). This means that the ant will travel 10 ft in height. Since there are 20 stairs, we would be tempted that the ant travelled 20 ft in length, but we don't count the length corresponding to the last stair, since we're already at the top. This makes for 10 + 19 = 29 ft.
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Re: an ant on walk

by marcusking » Fri Feb 27, 2009 9:12 am
sanju09 wrote:A stairway 10 ft high is such that each step accounts for half a foot upward and one-foot forward. What distance will an ant travel if it starts from ground level to reach the top of the stairway?

(A) 30 ft
(B) 33 ft
(C) 10 ft
(D) 29 ft
(E) 20 ft

OA D
Since each stair is 1/2 foot high and the stair case is 10ft high, there must be 20 steps.

We already know the ant has to travel 10 ft. up. And in order to reach the top it only has to go across nineteen 1ft. long stairs.

10 + 19 = 29.
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by krisraam » Fri Feb 27, 2009 12:12 pm
As each step is 1/2ft upward. A total of 20 steps are there.

The last step is the ant travels the height and reaches the top of the stairway.

its 10+19.

had it been the man taking the step it would have been 30.

Thanks
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by sanju09 » Sat Feb 28, 2009 5:11 am
krisraam wrote:As each step is 1/2ft upward. A total of 20 steps are there.

The last step is the ant travels the height and reaches the top of the stairway.

its 10+19.

had it been the man taking the step it would have been 30.

Thanks
raama
had it been the man taking the step it would have been 30.

I didn't get this. Will you please explain?
The mind is everything. What you think you become. -Lord Buddha



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by krisraam » Sat Feb 28, 2009 8:19 am
sanju09 wrote:
krisraam wrote:As each step is 1/2ft upward. A total of 20 steps are there.

The last step is the ant travels the height and reaches the top of the stairway.

its 10+19.

had it been the man taking the step it would have been 30.

Thanks
raama
had it been the man taking the step it would have been 30.

I didn't get this. Will you please explain?
When a man takes a step he takes one step at a time. each step is one unit and can't be divided. As each step taken is one and half feet distance covered. He takes 20 steps and covers 30ft.

Note :: The mans takes one step only to cover the stair step...

Thanks
raama

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by sanju09 » Mon Mar 02, 2009 4:07 am
krisraam wrote:
sanju09 wrote:
krisraam wrote:As each step is 1/2ft upward. A total of 20 steps are there.

The last step is the ant travels the height and reaches the top of the stairway.

its 10+19.

had it been the man taking the step it would have been 30.

Thanks
raama
had it been the man taking the step it would have been 30.

I didn't get this. Will you please explain?
When a man takes a step he takes one step at a time. each step is one unit and can't be divided. As each step taken is one and half feet distance covered. He takes 20 steps and covers 30ft.

Note :: The mans takes one step only to cover the stair step...

Thanks
raama
As each step taken is one and half feet distance covered.

Are you sure at it , raama?
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
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