SOLUTION: An athlete can jog at twice her walking pace. By walking for a total of 1h 40 mins and jogging for a total of 30 minutes she covers a total distance of 16km. What is her walking pa

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Question 1109742: An athlete can jog at twice her walking pace. By walking for a total of 1h 40 mins and jogging for a total of 30 minutes she covers a total distance of 16km. What is her walking pace in kilometres per hour (kph)?
Found 3 solutions by josmiceli, josgarithmetic, TeachMath:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Convert minutes to hrs
+40%2A%281%2F60%29+=+2%2F3+ hrs
+1+%2B+2%2F3+=+5%2F3+ hrs
and
+30%2A%281%2F60%29+=+1%2F2+ hrs
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Let +r+ = the walking pace
+2r+ = jogging pace
Let +d+ = distance walking in km
+6+-+d+ = distance jogging in km
-----------------------------
(1) +d+=+r%2A%285%2F3%29+
(2) +6+-+d+=+2r%2A%281%2F2%29+
-----------------------------
(2) +d+=+6+-+r+
Plug (1) into (2)
(2) +6+-+r%2A%285%2F3%29+=+r+
(2) +18+-+5r+=+3r+
(2) +8r+=+18+
(2) +r+=+2.25+
-----------------------
Her walking pace is 2.25 km/hr
--------------------------------------
check:
(1) +d+=+%289%2F4%29%2A%285%2F3%29+
(1) +d+=+15%2F4+
and
(2) +6+-+15%2F4+=+9%2F4+
(2) +6+=+24%2F4+
(2) +6+=+6+
OK

Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
r, rate walking
2r, rate jogging

r%2A%281%262%2F3%29%2B%282r%29%281%2F2%29=16
Simplify and solve.

Answer by TeachMath(96) About Me  (Show Source):
You can put this solution on YOUR website!
With her walking pace being S, her jogging speed = 2S
A time equation can then be formed. This is: (1 40/60)S + 2S(30/60) = 16
Solving this results in a walking pace of 6 km/h