There is an order of 19000 quantity of a particular product from a customer. The firm produces 1000 quantity of that product per day out of which 5% are unfit for sale. In how many days will the order be completed ?

Okay, let's break this down. The target is 19000 items. The company makes 1000 items a day, but 5% are faulty and can't be sold. First, I need to figure out how many *good* items they make each day. This is a simple percentage calculation, which comes up all the time in CSAT [18, 19, 74]. 10% of 1000 is 100, so 5% is half of that, which is 50. So, 50 items are faulty each day. The number of good items is 1000 - 50 = 950 per day. Now this is a standard work and time problem, just like those pipes questions from 2015 [2, 3]. I need to find the number of days to make 19000 items at a rate of 950 per day. So, Days = Total / Rate = 19000 / 950. To simplify, I can knock off a zero from both numbers, which gives 1900 / 95. I can spot that 95 multiplied by 2 gives 190. So, 1900 divided by 95 must be 20. The order will be completed in 20 days.