A garments factory employs 3 categories of workers K, M and N. The efficiency of the 3 categories of workers to do a specific task is in the ratio of 3 : 5 : 6 respectively and the factory employs 15 of category K, 12 of category M and 3 of category N. If the total wages paid to the entire group of 30 workers is Tk. 492 per hour, what will be the wages earned by a category N worker for an 8-hour day?