work rate

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work rate

by jainrahul1985 » Sun Jul 26, 2009 8:55 am
One hour after Yolanda started walking from X to Y, a distance of 45 miiles, Bob started walking along the same road from Y to X. If Yolanda's walking rate was 3 miles /hour and Bob's was 4 miles / hour, how many miles had Bab walked when they met?
24
23
22
21
19.5
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by shibal » Sun Jul 26, 2009 8:59 am
simple, when anything comes from opposite directions, u add both rates.

yolanda walked 3 miles, so the distance between the 2 of them is 42.
42/7=6

6*4=24

hope it helps.....

MY GMAT IS TOMORROW PRAY FOR ME!!!!!

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by jainrahul1985 » Sun Jul 26, 2009 9:08 am
Best of luck for the exam . May god bless you . Please let me know about ur exam tomorrow .

I need 1 favour . Can you please explain above reply in little more detail . I am week in Work rate questions .

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by shibal » Sun Jul 26, 2009 9:21 am
amen!!!

try to picture both yolanda and bob in oppsoite sides of a road.... they are walking at different rates towards each other (45m).

it says that yolanda walked for an hour. her rate is 3mph, therefore she walked 3m, so thye are 42miles apart.

now bob starts walking at 4mph, and yolnada si already walking 3mph. the rule for combined rate is that when objects are moving toward each other you add both rate. but if you didn't know that, try to picture them walking each hour towards each other.

so after the 2nd hour, yolanda walked 6mp (3*2) and bob 4 miles, they are still 35m apart.... continue this logic and u'll see that after 6hours they meet each other.

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by PussInBoots » Mon Jul 27, 2009 9:51 pm
Good luck bro, please write your score in this thread (I flagged it in my RSS reader)