Question
The age ratio of 'P' and 'Q' 4 years ago was 7:6
respectively. 12 years from now, the ratio of their ages will be 11:10 respectively. What is the present age of 'Q'?Solution
ATQ,
4 years ago, let the age of 'P' and 'Q' be 7x years and 6x years respectively12 years hence,
Age of 'P' = 7x + 4 + 12 = (7x + 16) years
Age of 'Q' = 6x + 4 + 12 = (6x + 16) years
ATQ,
(7x + 16) / (6x + 16) = 11 / 10
⇒ 70x + 160 = 66x + 176
⇒ 4x = 16
⇒ x = 4
So, required age = 6 × 4 + 4 = 28 years
Train 'C' running with a speed of 90 km/hr crosses a pole in 8 seconds. In how much time will train 'C' cross train 'D' whose length is 80 meters more a...
- Train 'A' having a speed of 20 m/s can cross a man in 5 seconds. The length of train 'B' is 100 metres more than the length of 'A'. If the speed of 'B' is ...
A train that is 360 metres long passes a signal post in 18 seconds. How long will it take to pass a bridge that is 240 metres long?
Two poles are positioned at a certain distance from each other. A train traveling at a speed of 90 km/hr passes the first pole in 5 seconds and reaches ...
A train moving at a speed of 72 km/h takes 12.5 seconds to pass a pole. If the train takes 24 seconds to completely cross a platform, what is the lengt...
A train crosses a bridge in 15 secs while it crosses a man standing on a platform in 8 secs. If the speed of train 108 km/hrs, then what will be the ti...
- A train, running at the speed of 72 km/h, is 300 metres long. How much time (in seconds) will it take to pass over a bridge that is 600 metres long?
- A train can cross a bridge and a pole in 7.2 seconds and 4 seconds respectively. The length of the bridge is 80 metres. Find the time taken by train to cro...
Two trains A and B, were proceeding in the same direction on parallel tracks at 24 km/hr and 78 km/hr respectively. A man noticed that it took exactly 2...
Train ‘X’ is travelling with a speed of 90 km/hr and crosses a vertical pole in 6 seconds. Train ‘Y’ is 30 metres longer than ‘X’ and trave...
Relevant for Exams:
