What is the ratio between the present age of son and father? I. The ratio between the son's age after 5 years and father's age 10 years ago is 2 : 3 respectively. II. Twice the present age of son and father is 95 years.

Data sufficiency problem about ages. Let son's present age = x, father's present age = y. Statement I: (x+5)/(y-10) = 2/3, which gives 3(x+5) = 2(y-10), so 3x + 15 = 2y - 20, or 3x - 2y = -35. Statement II: 2x + 2y = 95 (interpreted as twice the sum of ages, which equals 95), so x + y = 47.5. Solving: from II, y = 47.5 - x. Substituting in I: 3x - 2(47.5 - x) = -35, giving 3x - 95 + 2x = -35, so 5x = 60, x = 12. Then y = 35. The ratio x:y = 12:35. Both statements are necessary.