1) What is the ratio between the ages of mother and the son? I) The sum of their ages is ages is 50 years.II) 3 times the sum of thier ages is equal to 5 times the mother's age. A) I) alone sufficient while II) alone not sufficient B) II) alone sufficient while I) alone not sufficient C) Either I) or II) alone sufficient D) Both I) and II) are not sufficient E) Both I) and II) are necessary Answer: Option BExplanation:M = MotherS = Son I) M+S=50−−−−−−−−(1)II) 3(M+S)=5M−−−−−(2) From II we get 2M−3S ⇔MS =32 Thus, (II) alone gives the answer, but (I) alone doesn't give the answer.∴ Correct answer is (B).