20. the value of the integral df.ds, where f-3 xi+2y j+zk and s is the closed surface given by the planes x = 0, x = 1y = 0, y 2, 2 = 0 and z = 3 is (b) 18 (d)3

20. The value of the integral dF.dS, Where F-3 xi+2y j+zk and S is the closed surface given by the planes x = 0, x = 1y = 0, y 2, 2 = 0 and z = 3 is (B) 18 (D)36 A) (C) 24