MHB Solve Work Rate Problem: Find A and B's Time Alone

  • Thread starter Thread starter Drain Brain
  • Start date Start date
  • Tags Tags
    Rate Work
AI Thread Summary
To solve the work rate problem, "A" takes two hours longer than "B" to complete a job. After "B" works alone for one hour, both work together for three additional hours to finish the job. The equations derived indicate that "B" requires 6 hours to complete the job alone, while "A" requires 8 hours. The discussion emphasizes the necessity of using time and rate equations to find the solution. Overall, the approach taken is deemed effective for solving the problem.
Drain Brain
Messages
143
Reaction score
0
I just want an alternative solution(preferably easier approach) to this problem

"A" can finish a job two hours longer than "B". After working for 1 hour, "B" joins him and they complete the job in 3 more hours. How long would it take "A" and "B" to finish a similar job if each worked alone?

my solution,

Let $B+2=$ A's required time to finish the job alone
$B=$ B's required time to finish the job alone

$\frac{1}{B+2}+3\left(\frac{1}{B+2}+\frac{1}{B}\right)=1$

solving for B I have

$B=6$hours
$A=8$hours

Regards!:)
 
Mathematics news on Phys.org
Well, I don't think there could be a much simpler way to solve this problem. You've got to work with times and rates like you're doing. There are two unknowns, which means you'd have to have two equations.
 
Seemingly by some mathematical coincidence, a hexagon of sides 2,2,7,7, 11, and 11 can be inscribed in a circle of radius 7. The other day I saw a math problem on line, which they said came from a Polish Olympiad, where you compute the length x of the 3rd side which is the same as the radius, so that the sides of length 2,x, and 11 are inscribed on the arc of a semi-circle. The law of cosines applied twice gives the answer for x of exactly 7, but the arithmetic is so complex that the...

Similar threads

Replies
1
Views
1K
Replies
6
Views
1K
Replies
10
Views
2K
Replies
1
Views
1K
Replies
4
Views
1K
Back
Top