A train is running at a uniform speed of 90 km/h. how much times does it take to cover a distance of 360 km? please help me
A)4h
B)5h
C)4h 30min
D)4h 40min please help me
Answers
Answered by
5
Answer:
option A) 4h is the correct
Step-by-step explanation:
speed=distance/time
so
time=distance/speed
time=360km/90km/h
time=4h
Answered by
0
Answer:
Correct option is
A
45
Let original speed =xkm/hr
⇒ Time taken to travel =
x
90
hr
⇒ New speed =(x+15)km/hr
⇒ Time taken to travel =
x+15
90
hr
∴
x
90
=
x+15
90
+
2
1
⇒
x
90
−
x+15
90
=
2
1
⇒ 90(
x
1
−
x+15
1
)=
2
1
⇒
x(x+15)
x+15−x
=
180
1
⇒ 15×180=x(x+15)
⇒ 2700=x
2
+15x
⇒ x
2
+15x−2700=0
⇒ x
2
+60x−45x−2700=0
⇒ x(x+60)−45(x+60)=0
⇒ (x+60)(x−45)=0
Speed can not be negative.
∴ The original speed of the train is 45km/hr
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