1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Summations problem

  1. Aug 31, 2012 #1
    1. The problem statement, all variables and given/known data
    Sum all the whole numbers which are multiples of 5 from 5 to 1550

    2. Relevant equations

    3. The attempt at a solution
    1550-5x310= 478950
  2. jcsd
  3. Aug 31, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Hint: Sum of arithmetic progression or, alternatively,$$
    \sum_{k=1}^{310}5k = 5\sum_{k=1}^{310}k$$
  4. Sep 1, 2012 #3


    User Avatar
    Science Advisor

    Yes, that is correct

    No, 1550- 5x 310= 0, That is what [tex]1550÷5= 310[/tex] means!
  5. Sep 1, 2012 #4


    User Avatar
    Science Advisor

    She is using the parentheses differently (incorrectly so , by priority of operations):

    1550-5=1545 , 1545x310= 474950
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook