Explanation:

- The average age of Rustam and Preetam is 39, so their combined age is 39 \* 2 = 78.

- The average age of Preetam and Geetam is 28, so their combined age is 28 \* 2 = 56.

- The average age of Rustam and Geetam is 34, so their combined age is 34 \* 2 = 68.

- Solving the above equations:

- R + P = 78

- P + G = 56

- R + G = 68

- By solving these equations:

- Subtract (P + G) from (R + P): R - G = 22

- Subtract (R + G) from (R + P): P - G = 10

- From this, we find:

- R = 45, P = 33, G = 23

- The youngest is Geetam at 23.

- After 10 years, Geetam will be 23 + 10 = 33 years old.

Option 3: 33 is correct.