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

First row: 32, 40, 18 

Second row: 38, 46, 21 

Third row: 33, 43, ? 

(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).