Question 1149972
RATES OF WORK
T_one, {{{1/15}}}
T_two, {{{1/w}}}
T_combined, {{{1/6}}}


x, unknown time for T_one to finish
{{{(1/6)*4+(1/w)*x=1}}}



Use the rates to solve for w.
Substitute in the "to finish" equation and simplify and solve for x.