SOLUTION: A brick layer can build a wall in 6 hours, and his apprentice would need 16 hours to build the same wall. When they work together, the apprentice works 5 hours longer than the bric

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A brick layer can build a wall in 6 hours, and his apprentice would need 16 hours to build the same wall. When they work together, the apprentice works 5 hours longer than the bric      Log On


   



Question 841655: A brick layer can build a wall in 6 hours, and his apprentice would need 16 hours to build the same wall. When they work together, the apprentice works 5 hours longer than the brick layer. How many hours does each work?
Found 2 solutions by richwmiller, josmiceli:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
x/6+(x+5)/16=1
They aren't working together if one is working longer than the other ie one is working when the other isn't working.
They each did half the job.
x = 3
x+5=8
check
3/6+8/16=1
1/2+1/2=1
ok

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The brick layer builds ( 1 wall ) / ( 6 hrs )
That's the same as ( 1/6 wall ) / ( 1 hour )
------------------------------------
The apprentice builds ( 1 wall ) / ( 16 hrs )
That's the same as ( 1/16 wall ) / ( 1 hour )
--------------------------------------
Let +t+ = the time that the brick layer works
+t+%2B+5+ = the timer the apprentice works
-----------------------------------------
( brick layer's rate ) x ( brick layer's time ) +
( apprentice's rate ) x ( apprentice's time ) = 1
( 1 is the whole job )
-----------------------------------------
+%28+1%2F6+%29%2At+%2B+%28+1%2F16+%29%2A%28+t+%2B+5+%29+=+1+
Multiply both sides by +48+
+8t+%2B+3t+%2B+15+=+48+
+11t+=+33+
+t+=+3+
+t+%2B+5+=+8+
the brick layer works 3 hrs
The apprentice works 8 hrs
----------------------------
check:
+%28+1%2F6+%29%2At+%2B+%28+1%2F16+%29%2A%28+t+%2B+5+%29+=+1+
+%28+1%2F6+%29%2A3+%2B+%28+1%2F16+%29%2A%28+3+%2B+5+%29+=+1+
+1%2F2+%2B+1%2F2+=+1+
OK