SOLUTION: Chandra can milk a cow in 1/2 the time of elsa. Together they can milk the cows in 45 minutes. How long would it take elsa to milk the cows by herself. Show how to find the answ

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Chandra can milk a cow in 1/2 the time of elsa. Together they can milk the cows in 45 minutes. How long would it take elsa to milk the cows by herself. Show how to find the answ      Log On


   

Question 435587: Chandra can milk a cow in 1/2 the time of elsa. Together they can milk the cows in 45 minutes. How long would it take elsa to milk the cows by herself. Show how to find the answer
Found 2 solutions by stanbon, edjones:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Chandra can milk a cow in 1/2 the time of elsa. Together they can milk the cows in 45 minutes. How long would it take elsa to milk the cows by herself. Show how to find the answer
----
Together time = 45 min/job ; Together rate = 1/45 job/min
----
Chandra time = x min/job ; Chandra rate = 1/x job/min
----
Elsa time = 2x min/job ; Elsa rate = 1/2x job/min
======================================================
Equation:
rate + rate = together rate
1/x + 1/(2x) = 1/45
---
Multiply thru by 90x to get:
90 + 45 = 2x
---
2x = 135 min (Elsa time to do the job alone)
x = 67.5 min (Chandra time to do the job alone)
=====================
Cheers,
Stan H.
====================

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=time it takes chandra. 2x= time it takes elsa.
2x+x=45
3x=45
x=15 min
2x=30 min time it takes elsa.
.
Ed