You have ₹ 200 to spend on transport for 4 days. This works out to ₹ 50 per day. Therefore, you know that you need to take a bus (one-way fare ₹ 20) rather than an auto rickshaw (one-way fare ₹.50). On day 1, you take a bus to and fro and are able to stay within budget. On day 2, you are late and take an auto. Even if you take a bus back home, you will be ₹ 10 short or – ₹ 10 in spite of saving ₹ 10 the previous day. You will need to re-plan to adjust this deficit from the amount you have left. What amount do you have left for the remaining 2 ?