Using the same caselet from questions 29-32 (A shop sells items A and B. Item A: cost price Rs. 100, sold at 20% profit. Item B: cost price Rs. 200, sold at 25% profit. Total profit from 10 items is Rs. 350, with 5 items of A and 5 items of B sold), what is the percentage contribution of item A's profit to the total profit?