Problems based on Ages - Shortcut tricks
The below examples explains the simple way of solving problems on Ages.
Ex1: The ratio of the ages of Jhon and David is 3:5. After 9 years their ages will be in the ratio of 3:4. What could be the present age of David?
Solution: Their present age of Jhon = 3x and David = 5x.
==> (3x+9)/(5x+9) = 3/4
==> 4(3x+9) = 3(5x+9)
==> 12x+36 = 15x+27
==> 9 =3x
==> x = 3
:: David's Age = 5x ==> 5*3 = 15 years
Ex2: The sum of the ages of Jhon and David is 49. Also, 7 years ago David's age was 4 times Jhon's age. Find the present age of David.
View Answer
Solution: say Jhon's age 7 years ago is 'x'
==> David's age 7 years ago is 4x (4 times of Jhon's age)
==> (x+7)+(4x+7) = 49
==> 5x+14 = 49 ==> x=7
::David's present age = (4x+7) ==> 35 years
You could also look at below shortcut technics:
How To Solve Simplification Arithmetic Aptitude Questions
How To Solve Average Arithmetic Aptitude Questions