Question

Sequence question #1

Answer 1

Before being crazy, I still have to work for a while :)

Answer 2

what should i do..

Answer 3

Hmm... how would you do this question?

Answer 4

o.o ...I've work out the answer ...

Answer 5

for me this will take long to figure out..

Answer 6

this is an advanced topic..

Answer 7

@Callisto is like a genius. She figures stuff out so quickly

Answer 8

I got to admit that is true.. :)

Answer 9

No sol.

Answer 10

Since you work out the problem can you show the work? i'm trying to figure this out...(or is it called cheating?)
@castillo

Answer 11

let a and l be the first and the last term
Sum = (a+l)n/2 = n^3 +3n
(a+l)/2 = n+3
Consider the 'sum' of the first term
(a+a)/2 = 1+3
a =4

For the sum of the first 7 terms , where l= the 7th term now
(a+l)/2 = n+3
(4+l)/2 = 7+3
4+l =20
l =16
So the 7th term is 16

Answer 12

@Open2study I wish I were a genius. But unfortunately, I'm not :(

Answer 13

Oo .. i might have made some error.

Answer 14

Does anyone agree with my answer? I need to make sure I'm going to the right way

Answer 15

I turned out to have the same answer as you did..I guess its correct?
@Castillo

Answer 16

i agree ... I made subtraction error

Answer 17

(8^2+3*8) - (7^2+3*7) = must give you value.

Answer 18

looks like I got wrong ... 4,6,8,10,12,14,16,18,20,..

Answer 19

(8^2+3*8) - (7^2+3*7) .... is it the 8th term?

Answer 20

This must give 7th term: S7 - S6 = (7^2+3*7) - (6^2+3*6)

Answer 21

Its a good thing to look back on mistakes and fixing the error.. :)
It makes a good understanding..

Answer 22

@experimentX You're a genius!!!!!

Answer 23

calculational error !!!

Answer 24

lucky guess!!!

Answer 25

How silly am I..... :(

Answer 26

right on third guess. I am glad that I'm not a doctor.

Answer 27

but you are still a genius...even castillo... :)
@ experimentx and Castillo

Answer 28

I'm just happy to go lucky to be honest.

Answer 29

@experimentX Modesty :)

Answer 30

haha ... a little work, a little trick, and a lots of luck.

Answer 31

you are yourself pretty smart and sharp. you understand everything on a hint.

Answer 32

@experimentX Nope, I'm slow and silly :(

Answer 33

and you manage to solve many before I do.

Answer 34

That's because I focus on one question, but you're looking at different question at the same time lol

Answer 35

you really think that i must be super clever .... hahhah
i do that because I'm out of clue ... and most of questions posted here are childish.

Answer 36

super clever is not enough to describe you... :P