Correct Answer - Option 1 : 51
If all the 4 people were born between 1991 – 99, their ages at 2020 should be in the range 21 – 29
By year 2020
Let the age of the guys (from youngest to oldest) in the year 2020 be p, q, r and s respectively
Let sum of ages of two oldest guys and sum of ages two youngest guys be 9a and 8a respectively
9a and 8a should lie between 42 – 58 (Because sum of two people)
Only such value is possible when a = 6
Sum of ages of two youngest = p + q = 48 ---- 1
Sum of ages of two oldest = r + s = 54 ---- 2
By the year 2030
Their ages will be p + 10, q + 10, r + 10 and s + 10
Sum of ages of oldest + youngest: Sum of ages of other two guys = 1 ∶ 1
⇒ p + s + 20 = q + r + 20
∴ p + s = q + r
Equation 1 + Equation 2
⇒ p + s + q + r = 102
⇒ 2 × (q + r) = 102
⇒ q + r = 51 years
∴ The sum of the age of the third youngest guy and second youngest guy in the year 2020 is 51 years.