SOLUTION: A man cycled a distance of 42km from his village. On his return journey he increased his speed by 2km/hr and took half an hour less. Calculate the average speed on the journey from

Question 824121: A man cycled a distance of 42km from his village. On his return journey he increased his speed by 2km/hr and took half an hour less. Calculate the average speed on the journey from his village.
Found 2 solutions by Alan3354, josmiceli:
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
A man cycled a distance of 42km from his village. On his return journey he increased his speed by 2km/hr and took half an hour less. Calculate the average speed on the journey from his village.
-------------
d = r*t
42 = r*t
t = 42/r
t - 0.5 = 42/(r+2)
42/r = 0.5 + 42/(r+2)
Solve for r

Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = his rate going from the village in km/hr
Let = his time in hrs going from the village
-------------
Equation going from the village:
(1)
Equation for return journey:
(2)
-------------------------
(2)
(2)
(2)
(2)
-----------------------------
(1)
By substitution:
(1)
Multiply both sides by
(1)
(1)
(1)
(1)
-----------------------

His average rate traveling from the village was 12 km/hr
check:
(1)
(1)
(1)
-----------------
(2)
(2)
(2)
(2)
OK

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