SOLUTION: A AND B WORKING TOGETHER TAKE 8 AND 18 LESS DAYS THAN A ALONE AND B ALONE RESPECTIVELY TO DO A WORK. THE NUMBER OF DAYS TAKEN BY A AND B WORKING TOGETHER TO DO THE WORK IS?
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: A AND B WORKING TOGETHER TAKE 8 AND 18 LESS DAYS THAN A ALONE AND B ALONE RESPECTIVELY TO DO A WORK. THE NUMBER OF DAYS TAKEN BY A AND B WORKING TOGETHER TO DO THE WORK IS?
Log On
Question 1052907: A AND B WORKING TOGETHER TAKE 8 AND 18 LESS DAYS THAN A ALONE AND B ALONE RESPECTIVELY TO DO A WORK. THE NUMBER OF DAYS TAKEN BY A AND B WORKING TOGETHER TO DO THE WORK IS? Found 2 solutions by josgarithmetic, ikleyn:Answer by josgarithmetic(39838) (Show Source):
You can put this solution on YOUR website! Keep rechecking and thinking between this table of data and the description, until you understand how this table shows the description.
PERSON TIME for 1 job
A x
B y
A&B x-8 and y-18
You need to understand this: The combined work rate of A and B is the sum of their individual rates. The unit for these rates is JOBS/DAY, or WORK/DAYS, whichever way you choose. Keep on reviewing all of this until it makes sense.
You can put this solution on YOUR website! .
A AND B WORKING TOGETHER TAKE 8 AND 18 LESS DAYS THAN A ALONE AND B ALONE RESPECTIVELY TO DO A WORK.
THE NUMBER OF DAYS TAKEN BY A AND B WORKING TOGETHER TO DO THE WORK IS?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Let x = THE NUMBER OF DAYS TAKEN BY A AND B WORKING TOGETHER TO DO THE WORK.
The the number of days for A to do the job working alone is (x+8), and
the number of days for B to do the job working alone is (x+18).
Then the standard equation for joint work is
= .
To solve it, multiply everything by x*(x+8)*(x+18). You will get
x*(x+18) + x*(x+8) = (x+8)*(x+18).
Simplify:
= , or
= 144.
Hence, x = = 12.
Answer. 12 days.
(