Monday, May 21, 2007

MATH PROBLEM OF THE DAY

A rancher is constructing a fence by stringing wire between posts 20 feet apart. If the fence is 400
feet long, how many posts must the rancher use?
(A) 18 (B) 19 (C) 20 (D) 21 (E) 22

10 comments:

  1. even i was wondering the same. is it not c? plz xplain!

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  2. D.. take a small eg. for 20 mts u need 2 posts.. 40 mts u need 3.. likewise for 400 mts u need. 400/20 + 1

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  3. the ans is D
    intitially he shouls set up a post and then continue fencing from there for every 20 meters so to cover 400 meters he requires 20 posts in between plus the post that he laid intially so the ans is 20+1=21 (d)

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  4. Ohh ya I got it...thks vish n raghu!!!

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  5. 2 posts ---- 20ft
    3 posts ---- 40 ft
    4 posts ---- 60ft
    n posts ---- 20(n-1)

    hence
    400 = 20(n-1)

    n=21 (d)

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