anonymous one year ago Find the sum of the given arithmetic series. 24 + 48 + 72 + 96 + ... + 480 a. 5280 c. 10080 b. 9576 d. 5040

1. anonymous

$480 = 24+ (n - 1) 24$

2. anonymous

$S_n = \frac{ 19(24+480) }{ 2 } = ?$

3. anonymous

4788

4. anonymous

doesn't seem to be in your option

5. anonymous

nope

6. anonymous

weird lol

7. anonymous

try the maths again maybe it was a miscalculation

8. anonymous

true enough

9. anonymous

its $S _{20} = \frac{ 20(24+480) }{ 2 } =5040$

10. anonymous

i think thats it

11. anonymous

thank you

12. anonymous

yw