Life of bulbs produced by two factories A and B are given below: Length of life (in hours): 550-650 650-750 750-850 850-950 950-1050 Factory A: (Number of bulbs) 10 22 52 20 16 Factory B(Number of bulbs) 8 60 24 16 12

The number of complaints received on 8 different days of two different models of mobile phones sold by a shop are as follows: Model A: 22 18 25 20 16 17 12 22 Model B: 16 14 22 12 14 20 10 12 What measure of central tendency should be used to determine which model is better? Find the measure of this central tendency and state which model has better performance?

A dietician wishes to mix together two kinds of food X and Y in such a way that the mixture contains at least 10 units of vitamin A, 12 units of vitamin B and 8 units of vitamin C. The vitamin contents of 1 kg food is given below: 1 kg of food X costs Rs. 16 and 1 kg of food Y costs Rs. 20. Find the least cost of the mixture which will produce the required diet?