In each of the given number-clusters, the number on the right side of '=' (the equal to sign) is calculated by performing certain mathematical operations on the three numbers on the left of '=' (the equal to sign). All three number-clusters follow the same pattern. Select the number from among the given options that can replace the question mark (?) in the third number-cluster. 21, 9, 40 = 149 18, 7, 25 = 101 15, 11, 30 = ?