Question

Solve this ONE :-

Q-) Problem on SERIES.


6,20,36,48,50,?,0

a)36
b)40
c)46
d)56

Which number comes in place of "?" ?

Answer 1

@ash2326 @phi @UsukiDoll

Answer 2

56?

Answer 3

how?

Answer 4

Ned Flanders

Answer 5

what?

Answer 6

@INeedHelpPlease? help me

Answer 7

Tn = 7n^2 - n^3
T1 = 7(1)^2 - (1)^3 = 6
T2 = 7(2)^2 - (2)^3 = 20
....
...
T6 = 7(6)^2 - (6)^3 = 78
T7 = 7(7)^2 - (7)^3 = 0

so, it is T6 = 78

Answer 8

but it is not in options. @RadEn

Answer 9

i know this is also a answer but i need answer which is in options?

Answer 10

@hartnn can you help me ?

Answer 11

how did u get Tn RadEn ?

Answer 12

@RadEn's reasoning checks out, his answer should be 36 though. \(7(6^2)-6^3=252-216=36\)

Answer 13

he makes the series to solve it. @hartnn

Answer 14

yeah,
i know how to find Tn,
but i wanted to know whether RadEn used any different/simpler method....

Answer 15

his method is wrong.

Answer 16

he got the answer which is in the choices, how u say its wrong ?

Answer 17

because if we put n=6,the answer comes to be is 36 but in actual(followed by series)the answer would be 50

Answer 18

isiliye mujhe lagta h ki voh galat h

Answer 19

" in actual(followed by series)the answer would be 50"
what does this even mean ?

Answer 20

iska matla agar hum uske tarike se follow karien to iska answer 50 aana chaihye series ke hisaab se lekin actual main 36 aa raha h.....

iska method thode se hi digits ke liye apply hota h

Answer 21

now understood @hartnn bhaiya

Answer 22

lol, i could translate that in hindi myself too

Answer 23

why u say answer should be 50 ?

Answer 24

bhaiya , yeh question ntse 2013 RAJ. main poocha gaya tha aur FIITJEE vaalein bata rahein h ki iska answer DATA INADEQUATE h aur CAREER POINT vallein bata rahein h ki iska answer 36 h

Answer 25

to iska kya answer hoga bhaiya?

Answer 26

@hartnn

Answer 27

the answer to this is indeed 36
as shown corretly by RadEn

Answer 28

okk...thank you,,, @hartnn and @RadEn

Answer 29

i just wanted to know any simpler way of finding Tn :P

Answer 30

yeah...this logic doesn't apply in NTSE STAGE 1

Answer 31

i think there is another logic simpler logic for this

Answer 32

i think it does apply,
the third differences are constant