Question

What is the sum of the arithmetic sequence 9, 14, 19, …, if there are 34 terms?

Answer 1

9+(34*5)... maybe

Answer 2

No, sorry, 9+(33*5)

Answer 3

Ans Choices
A- 3,077

B-3,111

C-3,145

D-3,179

Answer 4

Yeah nvm what I said earlier

Answer 5

It would be 9+(5*1)+(5*2)+...(5*33), so you need the sum of 1+2+3+4...+33, and then multiply that by 5, and finally add 9.

Answer 6

you will get the 34th term by using @Snipa420 's method

Answer 7

So what is 1+2+3+...33

Answer 8

Isnt there some math function that makes adding consecutive whole numbers much simpler?

Answer 9

now use the formula the sum of an a.p = \[n/2(a+t)\]

Answer 10

where n is the number of terms,a is the 1st term, t is the last term...here t is the 34th term

Answer 11

Okay so @sritama , 1+2+3+...33=561. 561*5=2805, and 2805+9=2814

Answer 12

if you solve it,you will get 3111

Answer 13

thanks (:

Answer 14

:O...

Answer 15

@Snipa420 there is no need of adding 1+2+3+....+33 i guess

Answer 16

I must have done a calculation error.

Answer 17

What is your method @sritama

Answer 18

from the formula you wrote first, we will get the 34th term..it is 174

Answer 19

My second slapjob formula makes sense though...I think.

Answer 20

so now using the sum of a.p formula, we can write