"Tom and Jerry have cereal every morning. It would take Tom alone 6 days longer to finish a whole box of cereal than it would take Jerry. Together they eat the whole box in 4 days. How many days does it take Jerry to eat the whole box?"
Here's what I did:
x= Jerry's rate
x+6 Tom's rate
In a day Jerry does 1/x of the job and Tom does 1/(x+6) and together the do 1/4 of the job so
1/x+1/(x+6) =1/4
multiply both sides by (x)(x+6)(4)
4(x+6)+ 4x =(x)(x+6)
4x+24+4x=x^2+6x
8x+24=x^2+6x
24=x^-2x
0=x^2-2x-24
(x-6)(x+4)
x=6 or x=-4
Since you cant have -4 days.. it would take Jerry 6 days
Did I do this right?
2007-07-22 17:53:40 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
1/12 + 1/6 is 3/12, so I think you are right.
12/3 is 4 days.
12 days is slow guy.
6 days is fast guy.
4 days is both.
1/12 + 1/6 is 3/12, so 12/3 is 4.
2007-07-22 18:00:56 · answer #1 · answered by winter_new_hampshire 4 · 2⤊ 0⤋
You did it wrong
x=Jerry
y=Tom
y=x+6
x+y=4
x+y=4
since y is equal to x+6 you can just put it to the equation
the equation will look like this
x+(x+6)=4
you can reduce the equation
2x=4-6
this also equal to
x=(4-6)/2
x=(-2)/2
x=(-1)
Jerry's rate=(-1)
y=x+6
y=(-1)+6
y=5
Tom's rate=5
Checking
x+ y=4
=(-1)+6=4
y=x+6
y=(-1)+6
y=5
If you check your answer, you will find your answer is wrong
y=x+6
x+y=4
x+(x+6)=4
(-4)+((-4)+6) is not equal to 4
ps. It would take Tom six days longer than Jerry didn't mean it takes Tom six days.
2007-07-23 01:16:48 · answer #2 · answered by e963851surrey 3 · 0⤊ 1⤋
That's impressive. Give your self a well-earned bowl of cerial.
2007-07-23 01:03:52 · answer #3 · answered by cattbarf 7 · 0⤊ 0⤋
That's right.
2007-07-23 01:01:44 · answer #4 · answered by Jade C 3 · 0⤊ 0⤋
yeap correct!
2007-07-23 01:01:36 · answer #5 · answered by camila f 2 · 0⤊ 0⤋
everyone seems to think so , so YES!
2007-07-23 01:06:24 · answer #6 · answered by zanthus 5 · 0⤊ 0⤋