Question

when boy was of 6, his sister was half of him. now boy is 70, what is the present age of his sister??

Answer 1

his sister age s 35 because it is half of boy.So, we will divide 70 by 2 which gives 35.

Answer 2

Your Age = 6 = a

Sister age = a : 2 = b

Solution a: (incorrect)

Your age now = 70 = c

Sister age now = c : 2 = d = 35

Solution b: (correct)

Your age now = 70 = c

Sister age now = c - a : 2 = 67 = d

Conclusion:

Only first answer is mathematically correct. But if we apply the normal aging “laws” we say that solution b is correct but it ismathematically incorrect. Solution a is mathematically correct, but not by aging “laws”.

The solution is: Your sister age now is 67.