A boy runs for 10 min at a uniform speed of 9 km/h. At what
speed should he run for the
next 20 min so that the average speed comes to 12 km/h?
can anyone tell me ths ans?
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Answered by
2
Answer:
40 km plz mark as brainlist
Answered by
0
Answer:
s
1
=v
1
t
1
And, s
2
=v
2
t
2
Average speed v=
t
s
=
t
1
+t
2
s
1
+s
2
⟹v=
t
1
+t
2
v
1
t
1
+v
2
t
2
⟹v
2
=
t
2
v(t
1
+t
2
)−v
1
t
1
⟹v
2
=
20
12(10+20)−9×10
⟹v
2
=13.5km/h
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