curiousPope wrote:
There’s a lot of work in preparing a birthday dinner. Even after the turkey is in the oven, there’s still the potatoes and gravy, yams, salad, and cranberries, not to mention setting the table.
Three friends, Asit, Arnold, and Afzal, work together to get all of these chores done. The time it takes them to do the work together is six hours less than Asit would have taken working alone, one hour less than Arnold would have taken alone, and half the time Afzal would have taken working alone.
How long did it take them to do these chores working together?
(A) 20 minutes
(B) 30 minutes
(C) 40 minutes
(D) 50 minutes
(E) 60 minutes
HiBunuel ,
can you please help with thesolution.
Solving\(\frac{1}{t} =\frac{ 1}{(t +6)} +\frac{ 1}{(t +1)} +\frac{1}{2t}\) would beeasier:
\(\frac{1}{t} =\frac{ 1}{(t +6)} +\frac{ 1}{(t +1)} +\frac{1}{2t}\)
\(\frac{1}{t} -\frac{1}{2t} =\frac{ 1}{(t +6)} +\frac{ 1}{(t +1)}\)
\(\frac{1}{2t} =\frac{ (t + 1)+(t + 6)}{(t + 6)(t +1)}\)
\(\frac{1}{2t} =\frac{ 2t + 7}{(t + 6)(t +1)}\)
\( (t + 6)(t + 1)=2t(2t +7)\)
\( 3t^2 + 7 t - 6 =0\)
\( t=\frac{ 2}{3}\) or\( t =-3\).
Answer: C.
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Statistics : Posted by Bunuel • on 09 Jan 2020, 03:07 • Replies 4 • Views 8326
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