SOLUTION: Workman A's rate of doing work is twice that of Workman B's. One day, A & B work together for 8 hrs, then B due to injury stops and A finishes the rest of the job in 2 hrs. How lo
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: Workman A's rate of doing work is twice that of Workman B's. One day, A & B work together for 8 hrs, then B due to injury stops and A finishes the rest of the job in 2 hrs. How lo
Log On
Question 984443: Workman A's rate of doing work is twice that of Workman B's. One day, A & B work together for 8 hrs, then B due to injury stops and A finishes the rest of the job in 2 hrs. How long would it take B to complete the job alone? Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = the fraction of the job that
A & B get done in 8 hrs = the fraction of the job left
------------------------------------
After B stops working, A works at the rate: and finishes job
--------------------------------
You are told that A's rate is twice B's so
B's rate must be:
---------------------------------
Add their rates of working to get their rate
working together:
Multiply both sides by
and
-----------------
So, A can do 1/7 of the job in 2 hrs
A can do the whole job in 14 hrs
-----------------------------
This is twice B's rate, so B will take
28 hrs to do the job alone
-------------------------
check:
OK
