IBPS PO Exam: Quantitative Aptitude: Averages- Study Material

Institute of Banking and Personnel Selection (IBPS) will soon organize the Common Written Examination (CWE) for appointing the eligible candidates to the post of Probationary Officers in private sector banks. IBPS PO Exam 2013 will be conducted on 19 October 2013, 20 October 2013, 26 October 2013, and 27 October 2013. The common written examination contains 5 different subdivisions that are Reasoning, General Awareness, English Language, Quantitative Aptitude, and Computer Knowledge.
Quantitative Aptitude portion of the common written examination contains 40 questions on different topics such as Percentage Partnership and Share, Time & Work, Profit, Loss & Discount, Data Interpretation and more. For helping aspirants, Banking Experts of the Jagranjosh.com strive hard to provide best study material and practice paper.
This section contains study material on the topic, Averages. It is a very important part of quantitative aptitude sections.
Averages
The term Average refers to the sum of all observations divided by the total number of observations. Average is used quite regular in our day to day life. For example to calculate the average marks of the students, Average height of a particular group etc. The term average is also referred to as ‘Mean’. Basic formula to calculate the average is as follows:

Average = ( )

Example. What is the average of First 10 Prime numbers?

Solution: First 10 Prime number are 2,3,5,7,11,13,17,19,23,29.
                  Hence, Average = {2+3+5+7+11+13+17+19+23+29} / 10
                                                = 129 / 10
                                                = 12.90
So, Average of First 10 Prime numbers is 12.90.
Example. The total number of sales visits made by a Salesman in the month of June is 90. What is the Average visit he makes per day?
Solution: Number of days in the month of June are 30
                  Hence, Average Visit per day = Number of total visits / Number of total days
                                                                        = 90 / 30
                                                                        = 3
So, the salesman makes 3 visits per day.
Questions From Previous Year Papers:
1. The ratio between the speed of a truck, car and train is 3: 8: 12. The car moved uniformly and covered a distance of 1040 km in 13 hours. What is the average speed of the truck and the train together? (IBPS RRB Group ‘A’ Officers Exam 2012)
(1) 75km/hr
(2) 60 km/hr
(3) 48 km/hr
(4) Cannot be determined
(5) None of these
Solution. Speed of car
Ratio of speed of truck, car and train = 3 : 8 : 9
Now 8x = 80
∴ x = 10
Hence truck = 30 kmph.
Train = 90 kmph.
∴ Average speed of truck and train together
Ans: 2
2. The circumference of a circle is twice the perimeter of a rectangle. The area of the circle is 5544 sq cm. What is the area of the rectangle if the length of the rectangle is 40cm? (IBPS RRB Group ‘A’ Officers Exam 2012)
(1) 1120 sq cm
(2) 1020 sq cm
(3) 1140 sq cm
(4) 1040 sq cm
(5) None of these
Solution. Area of circle
∴ r = 42
Circumference of circle = 2 ⤬ perimeter of rectangle
Or,
Or, perimeter of rectangle = 132 cm
Or, 2(l + b) = 132
∴ l + b = 66
∴ b = 66 – 40 = 26
Area of rectangle = 40 ⤬ 26 = 1040 cm² = 1040 sq.cm.
Ans: 4
IBPS Bank PO Exam 2013: Complete Study Package
IBPS PO Exam 2013: Quantitative Aptitude (E Book)
IBPS PO Exam 2013: Tips and Strategies