Jacob bought 5 notebooks and 2 pens for Rs120. He told to guess the cost of each notebook and pen to his friends David and Anil. Jacob has given the clue that both the costs are divisible by 5 such that the cost of notebook is greater than that of a pen. Now David and Anil tried to guess. David said that price of each notebook could be Rs 18. Then five notebooks would cost Rs 90, the two pens would cost Rs 30 and each pen could be for Rs. 15. Anil felt Rs 18 for one notebook was too little. It should be at least Rs 20. Then the price of each pen would also be Rs 10