document.write( "Question 699066: \"This is the problem. Would you please help me with this? Thank You!\" ---> A and B working together can finish a certain job in 20/3 hours. They start the work together but after 3 hours. A became ill and B continuing the work alone finished it in 33/4 hours. How long would it take each working alone to do the job? \n" ); document.write( "
Algebra.Com's Answer #431291 by ankor@dixie-net.com(22740)\"\" \"About 
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A and B working together can finish a certain job in 20/3 hours.
\n" ); document.write( " They start the work together, but after 3 hours, A became ill and B continuing the work alone. finished it in 33/4 hours.
\n" ); document.write( " How long would it take each working alone to do the job?
\n" ); document.write( ":
\n" ); document.write( "let a = A doing the job alone
\n" ); document.write( "let b = B doing it alone
\n" ); document.write( ":
\n" ); document.write( "Let the completed job = 1
\n" ); document.write( ":
\n" ); document.write( "Write a share work equation for the statement:
\n" ); document.write( "\"A and B working together can finish a certain job in 20/3 hours.\"
\n" ); document.write( "\"%2820%2F3%29%2Fa\" + \"%2820%2F3%29%2Fb\" = 1
\n" ); document.write( "invert the divisor and multiply
\n" ); document.write( "\"20%2F%283a%29\" + \"20%2F%283b%29\" = 1
\n" ); document.write( "multiply by 3ab, results
\n" ); document.write( "20b + 20a = 3ab
\n" ); document.write( ":
\n" ); document.write( "\" They start the work together but after 3 hours, A became ill and B continuing the work alone, finished it in 33/4 hours. How long would it take each working alone to do the job?\"
\n" ); document.write( ":
\n" ); document.write( "Change 33/4 hrs to 8.25 hrs
\n" ); document.write( "B works 3 + 8.25 = 11.25 hrs
\n" ); document.write( "\"3%2Fa\" + \"11.25%2Fb\" = 1
\n" ); document.write( "multiply by ab to clear the denominators
\n" ); document.write( "3b + 11.25a = ab
\n" ); document.write( ":
\n" ); document.write( "Try to use elimination with these two equations
\n" ); document.write( "3b + 11.25a = ab
\n" ); document.write( "20b + 20a = 3ab
\n" ); document.write( "Multiply the 1st equation by 20, multiply the 2nd equation by 3
\n" ); document.write( "60b + 225a = 20ab
\n" ); document.write( "60b + 60a = 9ab
\n" ); document.write( "-----------------subtraction eliminates b
\n" ); document.write( "165a = 11ab
\n" ); document.write( "divide both side by a
\n" ); document.write( "165 = 11b
\n" ); document.write( "b = 165/11
\n" ); document.write( "b = 11 hrs working alone
\n" ); document.write( ":
\n" ); document.write( "Find a,
\n" ); document.write( "20b + 20a = 3ab
\n" ); document.write( "replace b with 11
\n" ); document.write( "20(11) + 20a = 3(a*11)
\n" ); document.write( "220 + 20a = 33a
\n" ); document.write( "220 = 33a - 20a
\n" ); document.write( "220 = 13a
\n" ); document.write( "a = 220/13
\n" ); document.write( "a = 16\"12%2F13\" hrs working alone
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check this in the 1st work statement equation but we will use decimals instead of those annoying fractions
\n" ); document.write( "\"6.67%2F16.92\" + \"6.67%2F11\" =
\n" ); document.write( ".394 + .606 = 1; confirms our solutions\r
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