SOLUTION: In solving the problem below, use a variable/s to represent the unknown quantity or quantities. Formulate the equation that will solve the problem. Solve the equation and check if

Algebra ->  Expressions-with-variables -> SOLUTION: In solving the problem below, use a variable/s to represent the unknown quantity or quantities. Formulate the equation that will solve the problem. Solve the equation and check if       Log On


   

Question 912783: In solving the problem below, use a variable/s to represent the unknown quantity or quantities. Formulate the equation that will solve the problem. Solve the equation and check if your solution is valid. Thank you!
Mr. B can finish a job in 9 hours. After working for 5 hours, he decided to take a rest. Mr. Twain helped Mr. B and finished the job in 2 hours and 20 minutes. How long would it take Mr. Twain to do the job alone?
Answer by josgarithmetic(39615) About Me  (Show Source):
You can put this solution on YOUR website!
(Adjusted mistake on Oct. 14, 2014):

Let T be the time for Mr. Twain to do the job alone.

Their rates:
Mr. B, 1/9
Mr. Twain, 1/T
B & Twain Combined, 1/9+1/T

The resting time is not important in the problem.

The whole job was split into two parts. Mr B for 5 hours and both workers for 2 hours 20 minutes.

highlight%28%281%2F9%295%2B%281%2F9%2B1%2FT%29%282%261%2F3%29=1%29
Solve the equation for T.

Just to help you be more confident, this is a work or task problem with uniform rates using the basic rule RT=J rate time job. In the example problem, the amount of job to be done is 1 job.