Time = distance/speed
Now, express train takes 1 hour less than a passenger train to travel 132 km between Mysore and Bangalore. The average speed of the express trains is 11 km / hr more than that of the passenger train.
Let the average speed of passenger train be ‘a’.
\(\frac{132}{a}-\frac{132}{a+11}=1\)
⇒ 132 ×(a + 11 –a) = a2 + 11a
⇒ a2 + 11a – 1452 = 0
⇒ a2 + 44a – 33a – 1452 = 0
⇒ a(a + 44) – 33(a + 44) = 0
⇒ (a + 44)(a – 33) = 0
⇒ a = 33 km/hr
Speed of express train = 44 km/hr
speed of passenger train`= x`km/hr
speed of express train `=(x+11)`km/hr
time taken by passenger train`= 132/x = 132/x`
time taken by express train`=132/(x+11) = 132/(x+11)`
acc to question
`132/(x+11) =132/x – 1 `
`132[1/x – 1/(x+11)] = 1`
`132[(x+11-x)/(x(x+11))]=1`
`132*11 = x(x+11)`
`x^2+11x-1452=0`
`x^2 + 44x-3x- 1452=0 `
`x(x+44) – 33(x+44)=0`
`(x-33)(x+44)=0`
`x=33 , -44`
x=-44 cant be possible as x cant be zero
so, x=33 & `x+11 = 44` answer