Study the given pattern carefully and select the number that can replace the question mark (?) in it. First row: 42, 54, 39 Second row: 78, 51, 56 Third row: 66, 36, ? (NOTE: Operations should be performed on the whole numbers, without breaking down the numbers into its constituent digits. E.g. 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)