SOLUTION: Brett usually takes 50 min. to groom the horses. After working 10 min., he was joined by Angela and they finished the grooming in 15 min. How long would it have taken Angela worki

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Brett usually takes 50 min. to groom the horses. After working 10 min., he was joined by Angela and they finished the grooming in 15 min. How long would it have taken Angela worki      Log On


   



Question 255439: Brett usually takes 50 min. to groom the horses. After working 10 min., he was joined by Angela and they finished the grooming in 15 min. How long would it have taken Angela working alone?
Found 2 solutions by ankor@dixie-net.com, stanbon:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Brett usually takes 50 min. to groom the horses.
After working 10 min., he was joined by Angela and they finished the grooming in 15 min.
How long would it have taken Angela.
:
Let t = time required by Angela alone
:
Total time worked by Brett: 10 + 15 = 25 min
:
Let the complete job = 1
:
25%2F50 + 15%2Ft = 1
:
1%2F2 + 15%2Ft = 1
Multiply by 2t
t + 2(15) = 2t
30 = 2t - t
t = 30 min Angela alone
;
:
Check solution
25%2F50 + 15%2F30 = 1

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Brett usually takes 50 min. to groom the horses. After working 10 min., he was joined by Angela and they finished the grooming in 15 min. How long would it have taken Angela working alone?
-----
Brett DATA:
time = 50 min/job ; rate = 1/50 job/min
------------------------------------------
Angela DATA
time = x min/job ; rate = 1/x job/min
------------------------------------------
Equation:
Note: together rate = 1/50 + 1/x = (x+50)/50x job/min
----
Brett work alone + together work = 1 job done
(1/50)(10) + [(x+50)/50x](15) = 1
(1/5) + (15x + 750)/50x = 1
(15x + 750)/50x = 4/5
(15x+750)/10x = 4
40x = 15x+750
25x = 750
x = 30 minutes (amount of time Angela would require to do the job alone)
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Cheers,
Stan H.