My fitness app gives me monthly challenge related to exercise each month. In June, the challenge was to complete 3600 minutes of exercise in the month. This averages to 120 minutes/ day as there are 30 days in the month of June. That means, If I do 120 minutes exercise each day of the June month, I total 3600 minutes which is equal to the challenge minutes. Average does this only. If average monthly expense in first 8 months of this year in your family is ₹25000, that means the total expense is ₹25000*8 = ₹200000. It is not necessary that the monthly expense is ₹25000 each month to keep the average same. Expenses may be high in some months and may be low too in some months. If the total expense in 8 months is ₹200000, then the average monthly expense is same ₹25000. Coming back to the exercise challenge. Doing 120 minutes of exercise each day was good enough for the June challenge. But, it's quite uncomfortable to keep doing that each day for 30 days. So, I divided the target of ...

  I purchased 7 mangoes from a nearby fruit seller yesterday as there were that many persons in my home. There are plenty of fruit sellers around, so there is no reason of purchasing more and storing. The fruit seller was a lady in her seventies and probably had no formal education. She sold those mangoes at ₹140/kg. She weighed the mangoes selected by me. It was 1 kg 750 gm. She asked me to pay ₹245 while transferring the mangoes into my bag. I was surprised as the time taken by her to do this calculation was practically nothing and she didn’t use calculator or pen-paper. I took more time than her to do this calculation manually and found the amount to be right. I thought, she might have got another customer earlier purchasing same quantity of mangoes, so she might just remember the amount! But, it was not so. I was curious to know her process of doing the calculation. She said; 14*7 = 98 for 700 gm, +₹7 for 50 gm = ₹105 for 750 gm. Add 140 for 1 kg. So, 140+105=₹245...