Mansi travels 300 kms to her native partly by train and partly by bus. She takes
4 hours, if she travels 60 kms by train and the remaining by bus. lf she travels 1 00 kms
by train and the remaining by bus, she takes 10 minutes longer. Find the average
speed of the train and the bus separately.
Answers
Step-by-step explanation:
So according to question and using
Time = \frac{Distance}{speed}Time=
speed
Distance
Total distance =300 km
Mansi travels 60 km by train and 300−60=240 by bus in 4 minute,
\frac{60}{x} + \frac{240}{y} = 4
x
60
+
y
240
=4
and 100 km by train, 300−100=200 by bus, and takes 10 minutes more,
\frac{100}{x} + \frac{200}{y} = 4 + \frac{1}{6} = \frac{24 + 1 }{6} = \frac{25}{6}
x
100
+
y
200
=4+
6
1
=
6
24+1
=
6
25
Now, let
\frac{1}{x} = a \:
x
1
=a
and
\frac{1}{y} = b
y
1
=b
then 60a+240b=4.............(1)
100a+200b=25/6----(2)
multiply (1) by 5 and (2) by 6 we get
300a+1200b=20..........(3)
600a+1200b=25...........(4)
Subtracting (3) and (4) we get
−300a=−5
a = \frac{1}{60}a=
60
1
Putting the value of a in (1) we get
60 \times \frac{1}{60} + 240b = 460×
60
1
+240b=4
\begin{gathered}240b = 3 \\ b = \frac{1}{80} \end{gathered}
240b=3
b=
80
1
Now ,
\begin{gathered} \frac{1}{x} = a \\ a = 60 km/h\end{gathered}
x
1
=a
a=60km/h
\begin{gathered} \frac{1}{y} = b \\ b = 80 km/h\end{gathered}
y
1
=b
b=80km/h
Hence, the speed of the train is 60 km/hr and the speed of the bus is 80 km/hr.
Let the speed of train and bus be u km/h and v km/h respectively.
According to the question,
....(i)
....(ii)
Let
The given equations reduce to:
60p + 240q = 4 ....(iii)
100p + 200q =
600p + 1200q = 25....(iv)
Multiplying equation (iii) by 10, we obtain:
600p + 2400q = 40....(v)
Subtracting equation (iv) from equation (v), we obtain:
1200q = 15
q =
Substituting the value of q in equation (iii), we obtain:
60p + 3 = 4
60p = 1
p =
:. p = , q =
u = 60 km/h , v = 80 km/h
Thus, the speed of train and the speed of bus are 60 km/h and 80 km/h respectively.
HOPE IT HELPS
PLEASE MARK ME BRAINLIEST ☺️