Nikhil gets ₹250 from his parents every week for his expenses. He puts ₹5 in his piggy bank on everyday except Sunday when he puts ₹10 in the piggy bank. He eats subsidized lunch in the college canteen for ₹ 10 on all college days except Saturday when he treats himself to the special lunch for ₹25. Bus fare to college is ₹4 each way. He has got a holiday on Sunday. This week, Nikhil wants to buy a book which costs ₹100. For this, he was walking to and from the college. He is le with ₹3 aer buying the book. Assuming no other expenses, how many times did Nikhil walk this week?