Discussion

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

First row:       17, 26, 60
Second row:   8, 15, 31
Third row:      11, 19, ?

(NOTE: Operations should be performed on the whole numbers, without breaking down the number into its constituent digits.
For example, 13 - Operations on 13 such as adding/deleting/multiplying etc. to 13 can be performed. Breaking down 13 into 1 and 3 and then performing mathematical operations on 1 and 3 is not allowed.)