Belly Dancers
If seven belly dancers can lose a total of 20 pounds in eight hours of dancing, how many more belly dancers would be needed to lose a total of 20 pounds in only four hours of dancing provided the new dancers shed weight only half as fast as the original dancers
Labels: mathemagic, trickofmind
posted by Rajesh Lal at
8:33 PM
16 Comments:
I say 14
Nevzat
21
21
yay
where do you guys get 21 from?
Nevzat
14 more are needed in addition to the original 7 for a total of 21.
i think that is where they got the 21 from.
I get 28:
7 dancers lose 20 pounds in 8hours
14 dancers lose 20 pounds in 4hours
The new dancers lose half as fast, so we double again:
28 dancers lose 20 pounds in 4hours
;-)
Yanon Mous
Fair enough, but the question did say how many MORE dancers are needed.
Nevzat
14 more..
14 new dancers is equiv to the original 8 dancers.. therefore adding 14 new dancers cuts the time in half..
14
7, because if they loose weight half as fast there is less of them needed not more and its 4 hours.
So we have:
7ppl=20lb=8hr
?ppl=20lb=4hr
they lose weight fast, so less of them are needed, since its 4 hours, you would only need 7
half as fast means they only shed half the weight as the others in the same amount of time... basically saying they go slower
This is my 2nd attempt as my first post went missing.
Original 7 belly dancers lose 20 pounds in 8 hours (or 10 pounds in 4 hours)
New 7 belly dancers lose 10 pounds in 8 hours (or 5 pounds in 4 hours)
Therefore 7 original dancers and 14 new ones are needed to lose 20 pounds in 4 hours.
I know the answers has been given already, but hopefully that explains it fully.
pramsay13
You need 21 more for a total 28 dancers.
They have 1/2 the time which is a factor of 2, they lose weight 1/2 as fast, another factor of 2. Therefore you need 4 times the original 7 minus the 7 you already have.
14 more. I forgot the original dancers still loose 10 pounds in 4 hours, so 14 more of the slow ones gives you 10 more pounds for a total 20.
I believe it is 28, but where do i find the answers?
why did i get 79?
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