Average - General QuestionsAverage - Important Formulas and Facts 1) Average = Sum of observations / Number of observations 2) Suppose an object covers a certain distance at 'a' kmph and an equal distance at 'b' kmph. Then the average speed during the whole journey = $\left(\frac{2ab}{a+b}\right)$
11.A grocer has a sale of Rs. 6435, Rs. 6927, Rs. 6855, Rs. 7230 and Rs. 6562 for 5 consecutive months. How much sale must he have in the sixth month so that he gets an average sale of Rs. 6500 ? A) Rs. 4991 B) Rs. 5991 C) Rs. 6001 D) Rs. 6991 View Answer Report DiscussAnswer: Option AExplanation:Total Sale for 5 months =6435+6927+6885+7230+6562=34009requires sale =[(6500x6)-34009]=39000-34009=4991
12.The average price of 10 books is Rs. 12 while the average price of 8 of these books is Rs. 11.75. Of the remaining two books, if the price of one book is 60% more than the price of the other, what is the price of each of these two books ? A) Rs. 5, Rs. 7.50 B) Rs. 8, Rs. 12 C) Rs. 10, Rs. 16 D) Rs. 12, Rs. 14 View Answer Report DiscussAnswer: Option CExplanation:Total price of the two books = [(12x10)-(11.75x8)] = 120-94 = 26Let the price of one book be xthen the price of the other book = (x+60% of x) = $x+\frac{3}{5}x=\frac{8x}{5}$So $x+\frac{8x}{5}=26$ => 13x=130=> x=10The price of the two books are Rs.10 and Rs.16
13.The batting average for 40 innings of a cricket player is 50 runs. His highest score exceeds his lowest score by 172 runs. If these two innings are excluded, the average of the remaining 38 innings is 48 runs. The highest score of the player is : A) 165 runs B) 170 runs C) 172 runs D) 174 runs View Answer Report DiscussAnswer: Option DExplanation:Let the highest score be x .then lowest scare = x-172Then 50x40-[x+(x-172)]=38x482x=2000+172-18242x=348x=174
14.The average of six numbers is 3.95. The average of two of them is 3.4, while the average of the other two is 3.85. What is the average of the remaining two numbers ? A) 4.5 B) 4.6 C) 4.7 D) 4.8 View Answer Report DiscussAnswer: Option BExplanation:Sum of the remaining two numbers =(3.95x6)-[(3.4x2)+(3.85x2)] = 23.70-(6.8+7.7) = 23.70-14.5 = 9.20required average =9.2/2= 4.6
15.16 children are to be divided into two groups A and B of 10 and 6 children. The average percent marks obtained by the children pf group A is 75 and the average percent marks of all the 16 children is 76. What is the average percent marks of children of group B ? A) $77\frac{1}{3}$ B) $77\frac{2}{3}$ C) $78\frac{1}{3}$ D) $78\frac{2}{3}$ View Answer Report DiscussAnswer: Option BExplanation:$\frac{(76\times16)-(75\times10)}{6}=\frac{1216-750}{6}=\frac{466}{6}=\frac{233}{3}=77\frac{2}{3}$
