Question
18 years ago the average age of a family of four members
was 45 years. Two children were born in that span of 18 years. The present average age of the family remained unchanged. Among the two children who were born in between the 18 years, if the older child at present is 12 years more than the younger one, what is the respective ratio between the present age of the older child and the present age of the younger child?Solution
18 years ago, The sum of age of a family of four members = 45 × 4 = 180 years Now at present, The sum of age of four members = 180 + 18 × 4 =252 years Let the Present age of younger child be x years And the present age of older child = (x + 12) years Now, as per the question 252 + x + 12 + x = 45 × 6 2x = 270 – 264 2x = 6 x = 3 Present age of the older child = x + 12 = 3 + 12 = 15 years Present age of the younger child = x = 3 years Respective ratio = 15 : 3 = 5:1
Two ladies simultaneously leave cities A and B connected by a straight road and travel towards each other. The first lady travels 3 km/hr faster...
A sprinter is 600 metres behind another runner and begins a chase at a speed of 22 m/s. If the runner ahead is moving at 14 m/s, find out the time it wi...
- A cyclist travelling at three-fourths of his usual speed takes 12 minutes longer than his usual time to cover a certain distance. Calculate the usual time ...
‘K’ and ‘L’ are going from place ‘X’ to place ‘Y’, which is 1100 km apart. If ‘K’ started 3 hours after ‘L’ but both of them rea...
Akash, during his journey, travels for 30 minutes at a speed of 20 km/h, another 20 minutes at a speed of 30 km/h, and 2 hour at a speed of 40 km/h and ...
Two cyclists P and Q are at towns A and B. P sets off toward B at (x – 8) km/h. Two hours later, Q starts toward A at (x + 8) km/h. They meet at the e...
Speed of a car and a bus is 20 km/h and 10 km/h, respectively. If the time taken by the car to cover a distance of ‘9x’ km is 4 hour less than time ...
- A boy standing on a hill hears the echo of a shot from a nearby cliff located 2.5 km away, after 28 seconds. Determine the approximate speed at which sound...
A,B and C run around a Circular track starting from the same point simultaneously and in the same direction at the speed of 8 kmph, 12 kmph and 16 kmph ...
A person crosses a 600-metre-long street in 10 minutes. The speed of the person, in km/h, is:
Relevant for Exams:
