top button
Flag Notify
    Connect to us
      Facebook Login
      Site Registration Why to Join

    Get Free Puzzle Updates

Facebook Login
Site Registration

What is the average of first 100 multiples of 5 ?

0 votes
632 views
What is the average of first 100 multiples of 5 ?
posted Aug 19, 2014 by Basabdatta Mukherjee

Share this puzzle
Facebook Share Button Twitter Share Button Google+ Share Button LinkedIn Share Button Multiple Social Share Button

3 Answers

+2 votes
 
Best answer

5x1 + 5x2 + 5x3 + 5x4 ..... 5x100 = 5 * (1 + 2 + 3 + 5 .... + 100)
= 5 * (sum of n numbers)

For calculating the sum of n numbers we have the formula
i.e (n * (n + 1)) / 2

apply the formula in the above equation.
where n = 100
so
= 5 * (100 * (100 + 1)) / 2
= 5 * (50 * 101)
= 5 * 50 * 101
= 25250
This the sum of the first 100 positive number which is multiples of 5.

And for average:
= 25250 /100
= 252.50

answer Aug 19, 2014 by Arshad Khan
+1 vote

Answer: 252.5

Solution: ((5 x 1) + (5 x 100)) / 2 = 252.5

answer Aug 19, 2014 by Indra M
0 votes

(5*((100*101)/2))/100=252.5

answer Aug 19, 2014 by Kamran Siddique



Similar Puzzles
0 votes

Out of three given numbers , the first one is twice the second and three times the third.
If the average of these numbers is 88, then what is the difference between first and third ?

0 votes

In an assessment the first 17 people scored an average of three points each. After a further 30 people had taken the assessment the average score rose to nine points each. What was the average number of points scored by the last 30 people only?

0 votes

The average age of a husband and wife was 23 years when they were married 5 years ago. The average age of the husband, the wife and a child who was born during the interval, is 20 years now.
How old is the child now?

Contact Us
+91 9880187415
sales@queryhome.net
support@queryhome.net
#280, 3rd floor, 5th Main
6th Sector, HSR Layout
Bangalore-560102
Karnataka INDIA.
QUERY HOME
...