SOLUTION: Cook made c cookies which fed s students for 10 days. How many days would it take m more students to eat the same amount of cookies? Thank you so much!!

Algebra ->  Human-and-algebraic-language -> SOLUTION: Cook made c cookies which fed s students for 10 days. How many days would it take m more students to eat the same amount of cookies? Thank you so much!!      Log On


   



Question 891499: Cook made c cookies which fed s students for 10 days. How many days would it take m more students to eat the same amount of cookies?
Thank you so much!!

Found 2 solutions by richwmiller, josmiceli:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Let's put in some numbers.
The baker made 200 cookies which fed 5 students for 10 days. How many days would it take 15 more students to eat the same amount of cookies?

200/5=40 c/s
40/10= 4 cookies a day c/10s cookies per day
add 15 students
200/20=10 c/(s+m)
10/4=2.5 days (c/(s+m))/(c/10s)
c=200 s=5 m=15
(c/(s+m))/(c/10s)=10s/(s+m)
10s/(s+m)









Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
It sounds like they want you to find out the
rate at which students consume cookies
Over +10+ days, the rate is +c%2F3+ cookies / student
--------------------------
The rate you want, though, is ( cookies / student ) / ( days to eat them )
+%28+c%2Fs+%29+%2F+10+=+c+%2F+%28+10s+%29+
----------------------------
Adding +m+ more students means you now have +s+%2B+m+ students
Let +d+ = the number of days for the +s+%2B+m+ students to
consume +c+ cookies
------------------------
You can set up the proportion:
( rate #1 ) = ( rate #2 )
+c+%2F+%28+10s+%29+=+c+%2F+%28+d%2A%28+s+%2B+m+%29+%29+
Multiply both sides by +10s%2A%28+d%2A%28+s+%2B+m+%29+%29+
+c%2A%28+d%2A%28+s+%2B+m+%29+%29+=+10s%2Ac+
Divide both sides by +c+
+d%2A%28+s+%2B+m+%29+=+10s+
+d+=+%28+10s+%29+%2F+%28+s+%2B+m+%29+ answer
--------------------------------
Check:
Let +c+=+100+
Let +s+=+20+
Let +m+=+5+
----------------
+%28+c%2Fs+%29+%2F+10+=+c+%2F+%28+10s+%29+
+c+%2F+%28+10s+%29+=+100+%2F+%28+10%2A20+%29+
+c+%2F+%28+10s+%29+=+1%2F2+
This is 1/2 a cookie per student per day
-------------------------------------
If you add +5+ more students,
+c+%2F+%28+d%2A%28+s+%2B+m+%29+%29+=+100+%2F+%28+d%2A%28+20+%2B+5+%29+%29+
+c+%2F+%28+d%2A%28+s+%2B+m+%29+%29+=+100+%2F+%28+25d+%29+
-----------------------------------
This is the same rate of eating, so
+1%2F2+=+100+%2F+%28+25d+%29+
+25d+=+200+
+d+=+8+
So 25 students go through 100 cookies
in 8 days instead of 10- hope that's right