Composition tax in karnataka/maharashtra

In case of Works Contract Services in Karnataka 4% tax is payable under composition scheme, i case i show material part (say Rs 60) and Labour Part ( say Rs 40) separately in the bill, whether i am supposed to pay composition tax on Rs 60 (only materials) or Rs 100 (on Material +Labour), Solution for transaction in Karnataka/maharashtra is required. thanks in advance