Merry-Go-Round
Whilst riding on a Merry-Go-Round, ToM noticed that the total number of riders was equal to one-third of those ahead of him plus three-quarters of those behind him. How many riders were there?
posted by Chris at
6:42 PM
7 Comments:
# riders =x
since merry go round is circle (x-1) riders, ahead or behind
ahead+behind+Tom=all riders
1/3*(x-1)+3/4(x-1)+1=x
1/3*x+3/4*x-1/3-1/4+1=x
13/12*x-1/12=x
x=1
Shocking only Tom is on the ride....
Did I err ?
Cam
I like your answer better than the correct one.
Found the mistake !
# riders =x
since merry go round is circle (x-1) riders, ahead or behind
ahead+behind+Tom=all riders
1/3*(x-1)+3/4(x-1)=x
1/3*x+3/4*x-1/3-1/4=x
13/12*x-13/12=x
-13/12=-1/12*x
x=13
13 are on the ride
Cam
13
on a merry-go-round,the person right ahead of you can still be behind you.
Luckily for you both, 13 isn't an unlucky number this time.
1/3 (x-1)+ 3/4 (x-1) + 1= x
(1/3 + 1/4) (x-1) + 1 = x
13x -13 + 1= 12x
x= 12
Hi SpArKo. You've made three mistakes. The +1 on your first line shouldn't be there. You changed 3/4 to 1/4 on your second line, but that was merely a typo. You forgot to multiply the erroneous 1 by 12 for your third line.
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