11. The following data represent the distribution of time (in minutes) needed to develop computer programs for solving some mathematical problems: Class 10 - 15 15 - 20 20 - 25 25 - 30 30 -35 Total Frequency 15 25 4 3 3 50 Comment on the skewness of the distribution. 17. Forty percent handsets produced by Walton are usually found defective. Walton produces 30 sets per day. Find the probability that in a particular day's production, there will be at best 2 defective sets. 20. A group of CSE students at AIUB were equally trained to develop a program. All of them had 50% chance to develop the program successfully. Ten randomly selected students were asked to develop the program separately. Find the probability that out of 10, none becomes successful