SOLUTION: brandon can shovel his sidewalk in 8 minutes nad his brother can shovel the sidewalk in 12 minutes. if they work together, how long will it take them to shovel the sidewalk?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: brandon can shovel his sidewalk in 8 minutes nad his brother can shovel the sidewalk in 12 minutes. if they work together, how long will it take them to shovel the sidewalk?      Log On


   



Question 212049: brandon can shovel his sidewalk in 8 minutes nad his brother can shovel the sidewalk in 12 minutes. if they work together, how long will it take them to shovel the sidewalk?
Found 2 solutions by stanbon, MathTherapy:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
brandon can shovel his sidewalk in 8 minutes nad his brother can shovel the sidewalk in 12 minutes. if they work together, how long will it take them to shovel the sidewalk?
--------------------------
Brandon rate = 1/8 job/min
----------------------
Brother rate = 1/12 job/min
--------------------------------
Together rate = 1/x job/min
Equation:
1/8 + 1/12 = 1/x
Multiply thru by 24x to get:
3x + 2x = 12
5x = 12
x = 2.4 minutes (time required when they work together)
Cheers,
Stan H.

Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!
brandon can shovel his sidewalk in 8 minutes nad his brother can shovel the sidewalk in 12 minutes. if they work together, how long will it take them to shovel the sidewalk?

Since Brandon can shovel the sidewalk in 8 minutes, in 1 minute, he will have shoveled 1%2F8 of the sidewalk

Since his brother can shovel the sidewalk in 12 minutes, in 1 minute, he will have shoveled 1%2F12 of the sidewalk

Let the time that both will take to shovel the sidewalk be B

We can then set up the proportion to determine the value of B, in munutes

%28%281%2F8%29+%2B+%281%2F12%29%29%2F1+=+1%2FB
%28%283+%2B+2%29%2F24%29%2F1+=+1%2FB
%285B%2F24%29+=+1 ------> Cross-multiplying

5B = 24

B+=+24%2F5 = highlight_green%284.8%29 minutes for both to shovel the sidewalk