Study the given pattern carefully and select the number that can replace the question mark (?) in it.

48	64	80
24	?	40
12	16	20

Given:

Logic: (1st column - 2nd column) $$\div$$  2 = 3rd column​

For, 1st column 

48 - 24 = 24, 24 $$\div$$​  2 = 12

For, 3rd column

80 - 40 = 40, 40 $$\div$$​  2 = 20

For, 2nd column

? $$\div$$​  2 = 16

? = 16 $$\times$$ 2 = 32

So, the missing value is 32.

Thus, correct option is (b).