Question 183405: Locate on ASVAB test on testpreview.com
Advanced Math Section-#8. If Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days, how long would the job take if Sam, Lisa, and Tom worked together to complete it?
Advanced Algebra-#3. Jim can fill a pool carrying buckets of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together?
I know the answer, but what was the solution in detail to arrive at the answer? What is the equation or formula I will use when taking during the test? Help I am stumped. Thanks
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!
This method works for all sorts of shared work problems. Painting rooms, pumping water in and out of a tank, mowing lawns, etc.
If A can do an entire job in x time periods, then A can do  of the job in 1 time period.
Likewise, if B can do an entire job in y time periods, then B can do  of the job in 1 time period.
Together, A and B can do  of the job in 1 time period.
Therefore, A and B can do the entire job in
time periods.
If you have three entities working together at three different rates, then add a factor to the numerator and a term to the denominator:
Said pattern can be extended indefinately.
Hint: If you have times given in different units, convert them all to the same unit before proceeding.
John
|
|
|
