<PRE><B>Question 959366</B>
LET X BE THE TIME FOR THE 5MPH RUN.
LET 1.8-X BE THE TIME FOR THE 6 MPH RUN.
D=RT
10=(5X+6(1.8-X))
10=5X+10.8-6X
10=-X+10.8
X=10.8-10
X=.8 HOURS FOR THE 5MPH RUN.
1.8-.8=1 HOUR FOR THE 6 MPH RUN.
PROOF:
10=5*.8+6*1 
10=4+6
10=10</PRE>