SOLUTION: kiran sets off on a walk at a speed
of 6km/h. 10 minutes later, her
brother Ali sets off her on his bicycle
at 15km/h. How far must Ali go to
catch up with Kiran?
Question 697453: kiran sets off on a walk at a speed
of 6km/h. 10 minutes later, her
brother Ali sets off her on his bicycle
at 15km/h. How far must Ali go to
catch up with Kiran? Found 2 solutions by stanbon, josmiceli:Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! kiran sets off on a walk at a speed
of 6km/h. 10 minutes later,
----
distance = rate*time = 6 km/hr*(1/6)hr = 1 km
------
her brother Ali sets after her on his bicycle
at 15km/h. How far must Ali go to
catch up with Kiran?
--
Kiran DATA:
rate = 6 km/hr ; time = t hrs ; distance = 6t km
----
Ali DATA:
rate = 15 km/hr ; time = t hrs ; distance = 15t km
----
Equation:
distance = distance
15t = 6t + 1
9t = 1
t = 1/9 hr.
----
Ali distance = 15t = 15(1/9) = 1 2/3 km or 5/3 km
==================
Cheers,
Stan H.
You can put this solution on YOUR website! Start a stopwatch when Ali leaves. By then,
Kiran has had a head start of hrs
and a distance of km
--------------
Let = the time in hrs on the stopwatch when
Ali catches Kiran.
Let = the distance in km that Ali travels
in time .
---------------
Kiran's equation:
(1)
Ali's equation:
(2)
----------------
(1)
Substitute (1) into (2)
(2)
(2)
(2)
(2)
and
(2)
(2)
(2)
Ali must travel 1.667 km to catch Kiran
check:
(1)
(1)
(1)
(1)
(1)
OK
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