<PRE><B>Question 255439</B>
Brett usually takes 50 min. to groom the horses.
 After working 10 min., he was joined by Angela and they finished the grooming in 15 min.
 How long would it have taken Angela.
:
Let t = time required by Angela alone
:
Total time worked by Brett: 10 + 15 = 25 min
:
Let the complete job = 1
:
{{{25/50}}} + {{{15/t}}} = 1
:
{{{1/2}}} + {{{15/t}}} = 1
Multiply by 2t
t + 2(15) = 2t
30 = 2t - t
t = 30 min Angela alone
;
:
Check solution
{{{25/50}}} + {{{15/30}}} = 1
 </PRE>