A train travels at a certain average speed of 120 and then travels a distance of 130 km at an average speed of 5 km hr more than is managed it takes 4 hours to complete the total journey. original speed of train
a)50
b)60
c)70
d)65
Answers
Answered by
1
Answer:
Distance =54 km
Let the average speed be x
Distance =63 km
The average speed to cover this distance =x+6
Total time taken =3 hr
t=
S
D
∴
x
54
+
x+6
63
=3
⇒
x(x+6)
54(x+6)+63x
=3
⇒54x+324+63x=3x
2
+18x
⇒3x
2
−99x−324=0
⇒x
2
−33x−108=0
⇒x
2
−36x+3x−108=0
⇒x(x−36)+3(x−36)=0
⇒(x−36)(x+3)=0
Then x=36 and x=−3
x=−3 is not admissible because it is negative
Then x=36
So speed =36 km/hr
Step-by-step explanation:
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Answered by
0
Hi army how are you
Be safe
Answer 50
Be safe
Answer 50
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