Two trains started at the same time, one from A to B and the other from B to A . If they arrived at B and A respectively 4 hours and 9 hours after they passed each other the ratio of the speeds of the two trains was
A) 2:1
B) 3:2
C) 4:3
D) 5:4
Answers
◀ HEY THERE!◀
◀ Question: ◀
→ Two trains started at the same time, one from A to B and the other from B to A . If they arrived at B and A respectively 4 hours and 9 hours after they passed each other the ratio of the speeds of the two trains was ?→
◀ Method of Solution: ◀
→ Let the Ratio of the Speeds of the two trains is a and b.
→ According to the Question's Statement!
→ Two trains started at the same time, one from A to B and the other from B to A.
⇒ A -----------------------------------B and B----------------------------------------A
Here,→ one from A to B = 'a'
One from B to A = 'b'
Note : ⇒
If they arrived at B and A respectively 4 hours and 9 hours after they passed each other , So it's Inversely proportional to each other's ,(if you write a:b it's meant √b:√a and if You take a²:b² it's meant b:a) So, Take (√a:√b).
⇒ Speed of A/ Speed of B = √b/√a
⇒Speed of A/Speed of B ⇒√9/√4.
→ Hence, Ratio of Speed of A is to Ratio of Speed of B = 3:2.
→ Therefore, Option C is the correct Answer.→
◀ Method ll : ◀
Let to be the total distance = x
⇒ Speed of A is (a)
⇒ Speed of B is (b)
→ According to the Question's Statement!
⇒ 4 ×a = x -------(1)
⇒ 9 × b = x -------(2)
◀ → From Equation (1) and (2) , RHS is Equal!→◀
⇒ 4×a = 9×b
⇒ •°• b/a= 2/3
→ Hence, a:b = 3:2 (Option C is correct Answer.)→
