Answer :
First of all, See the attachment for better understanding

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❂ Weight of block A :
➝ mg sin30° = 18
➝ W (1/2) = 18
➝ W = 18×2
➝ W = 36N
❂ Weight of block B :
➝ N sin30° = 18
➝ (Mg cos30°) sin30° = 18
➝ W' (√3/2)(1/2) = 18
➝ W' (√3/4) = 18
➝ W' = 72/√3
➝ W' = 41.61N