SOLUTION: A Photo scanner (A) can scan all the pictures in 2 hours and 15 minutes. Together, scanner (A) and scanner (B) can do the same work for 1 hour and 9 minutes. a. Which scanner is

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A Photo scanner (A) can scan all the pictures in 2 hours and 15 minutes. Together, scanner (A) and scanner (B) can do the same work for 1 hour and 9 minutes. a. Which scanner is      Log On


   



Question 1198409: A Photo scanner (A) can scan all the pictures in 2 hours and 15 minutes. Together, scanner (A) and scanner (B) can do the same work for 1 hour and 9 minutes.
a. Which scanner is more effective?
b. How much faster does it get the work done?

Answer by ikleyn(52864) About Me  (Show Source):
You can put this solution on YOUR website!
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A Photo scanner (A) can scan all the pictures in 2 hours and 15 minutes.
Together, scanner (A) and scanner (B) can do the same work for 1 hour and 9 minutes.
a. Which scanner is more effective?
b. How much faster does it get the work done?
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The rate of work of scanner (A) is  1%2F135  a job per minute,
    or 0.007407407 a job per minute.


The combined rate of work is  1%2F69 a job per minute, 
    or  0.014492754 a job per minute.


Hence, rate of job of  scanner (B) is  0.014492754 - 0.007407407 = 0.007085347 a job per minute.


Thus we see that the scanner (A) is more effective: its rate of work is higher.


Scanner (A) is  0.007407407%2F0.007085347 = 1.04545437 = 1.045 (rounded) times as fast as scanner (B).

Solved.

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On the way,  you learned a conception  " rate of work ",
which is the basic in solving such problems.