If one note book costs ₹15, one pen costs ₹ 9, and one pencil costs ₹5, then find the total cost of 5 notebooks, 6 pens and 4 pencils.
5 pencils and 7 pens together cost Rs. 50, whereas 7 pencils and 5 pens together cost Rs. 46. Find the costs of one pencil and one pen.