Aptitude ➤ Averages ➤ Set 1

#### Averages : Important Facts and Formulae

Average:
Average = Sum of observations / Number of observations

Average Speed :
Suppose a man covers a certain distance at x kmph and an equal distance at y kmph.
Then, the average speed druing the whole journey is [2xy/(x+y)] kmph.
Question 6
Q6.  A batsman makes a score of 87 runs in the 17th match and thus increases his average by 3. Find his average after 17th match .
Question 7
Q7.  Average weight of 15 students increased by 2 kg when one student of 50 kg is replaced by a fat student. Then weight of the new student is ?
Question 8
Q8.  A library has an average of 510 visitors on Sundays and 240 on other day. The average number of visitors in a month of 30 days starting with sunday is :
Question 9
Q9.  A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years. What is the average age of the family?
Question 10
Q10.  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?