Summations problem

  • Thread starter elainehula
  • Start date
  • #1

Homework Statement


Sum all the whole numbers which are multiples of 5 from 5 to 1550


Homework Equations





The Attempt at a Solution


1550÷5=310
1550-5x310= 478950
 

Answers and Replies

  • #2
LCKurtz
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Homework Statement


Sum all the whole numbers which are multiples of 5 from 5 to 1550


Homework Equations





The Attempt at a Solution


1550÷5=310
1550-5x310= 478950

Hint: Sum of arithmetic progression or, alternatively,$$
\sum_{k=1}^{310}5k = 5\sum_{k=1}^{310}k$$
 
  • #3
HallsofIvy
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Homework Statement


Sum all the whole numbers which are multiples of 5 from 5 to 1550


Homework Equations





The Attempt at a Solution


1550÷5=310
Yes, that is correct

1550-5x310= 478950
No, 1550- 5x 310= 0, That is what [tex]1550÷5= 310[/tex] means!
 
  • #4
Bacle2
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Yes, that is correct


No, 1550- 5x 310= 0, That is what [tex]1550÷5= 310[/tex] means!

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

1550-5=1545 , 1545x310= 474950
 

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