Question

A clock strikes once at 1:00, twice at 2:00, three times at 3:00 and so forth. How many times does it strike over a 12 hour period?

Answer 1

so we are finding the sum?

Answer 2

1+2+3+4+5+6+7+8+9+10+11+12?

Answer 3

Alright we can set that up like
1,2,3,4,5...12

Answer 4

You can do that too but that's not the way of answering it

Answer 5

DaWizjr math 20-1?

Answer 6

Since we need the sum of those numbers, the common difference here is 1,
\[\large S_n=\frac{n}{2}[2a_1+(n-1)d] \\ \\ \large S_{12}=\frac{12}{2}[2(1)+(12-1)1]=?\]

Answer 7

Try that out :)

Answer 8

N=12
a1 or t1=1:00
d=?

Answer 9

d is 1, because 2-1=1

Answer 10

ok

Answer 11

12=12/2[2(1)+(12-1)1]

Answer 12

guessing t1=1?

Answer 13

noo \(S_{12}\) is just a statement,
\[\frac{12}{2}[2(1)+(12-1)1]=?\]

Answer 14

Yea

Answer 15

\(T_1=a_1=1\)

Answer 16

I got 78

Answer 17

Correct

Answer 18

Nice