Train A takes 1 4/5 h more than the time taken by train B…

Comprehension:
In the following passage, some words have been deleted. Fill in the blanks with the help of the
alternatives given. Select the most appropriate option for each blank.
Graduation Day was at hand. Primary school graduation (1) ______ in those days followed a
prescribed order-conventional, courteous and (2) ______. First the school principal made a
long speech (3) ______ encouragement and blessing for the future of the graduates. (4) ______
one of the representatives of the graduating class (5) ______ with a vote of thanks.

Train A takes 1 $\frac{4}{5}$ h more than the time taken by train B to cover a distance of 360km. If the speed of train A doubles, it will take 36 min less than the time taken by train B to travel the same distance. What is the speed (in km/h) of train B?

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. 120

Time = Distance/Speed

Let the speed of train A = x

Let the speed of train B = y

As per the question;

360/x - 360/y = 9/5 hours

⇒ 1/x - 1/y = 1/200 (1)

360/y - 360/2x = 36/60 hours

⇒ 1/y - 1/2x = 1/600 (2)

By (1) ÷ 2 and then (1) + (2)

⇒ 1/2x - 1/2y + 1/y - 1/2x = 1/400 + 1/600

⇒ 1/2y = 5/1200

⇒ y = 120

SSC CHSL 2021 PYQ — Question 52