Let the two numbers be x and y.

According to question -

x + y = 16.....(1)

and,

⇒ 3x + 3y = xy.....(2)

From equation (1), we get -

x = 16 - y.....(3)

Substitute the value of x in equation (2), we get -

3(16 - y) + 3y = (16 - y)y

⇒ 48 = 16y - y²

⇒ y² - 16y + 48 = 0

⇒ y² - 12y - 4y + 48 = 0

⇒ y(y - 12) - 4(y - 12) = 0

⇒ (y - 4)(y - 12) = 0

⇒ y = 4 or y = 12

Case 1. When y = 4

x = 12 [from equation (3)]

Case 2. When y = 12

x = 4 [from equation (3)]

Thus, the possible values are 12 and 4.