# Summations problem

1. Aug 31, 2012

### elainehula

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÷5=310
1550-5x310= 478950

2. Aug 31, 2012

### LCKurtz

Hint: Sum of arithmetic progression or, alternatively,$$\sum_{k=1}^{310}5k = 5\sum_{k=1}^{310}k$$

3. Sep 1, 2012

### HallsofIvy

Staff Emeritus
Yes, that is correct

No, 1550- 5x 310= 0, That is what $$1550÷5= 310$$ means!

4. Sep 1, 2012

### Bacle2

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

1550-5=1545 , 1545x310= 474950