Edit: Oh never mind... It's a DS question lol... I'll go for...C???


Is OA 6??? the question doesn't say that n must be an integer but I'm assuming that...
Because when n = 8 the result is 10, all the values less than n = 8 will yield a result greater than 10. This is n = 2,3,4,5,6,and 7.

I did the math, but I think it's useless in this question

Recursive formula:
a(1) = a(0) + k = 24
a(8) = a(7) + k = 10

a(8) = a(1) + 7k = 10
a(8) = 24 + 7k = 10
7k = 10 - 24
7k = -14
k = -2

Lineal formula:
a(n) = kn + x
a(n) = -2n + x
a(1) = -2 + x = 24
-2 +x = 24
x = 24+2 = 26

Final formula -> a(n) = -2n + 26

atulmangal wrote:In the sequence shown above, a(n) = a(n-1) + k, where 2 <= n <= 15 and k is a non-zero constant. How many terms in the sequence are greater than 10?

(1) a(1) = 24 (2) a(8) = 10

atulmangal wrote:In the sequence shown above, a(n) = a(n-1) + k, where 2 <= n <= 15 and k is a non-zero constant. How many terms in the sequence are greater than 10?

(1) a(1) = 24 (2) a(8) = 10

I could not understand your quistion..

hi guys
it seems to me that i saw this prolem ealier so i `ii try to say why answer is B
clearly 1 st does not say anything, to the 2 st
(2) a(8)=10
a(n)=a(n-1)+k
a(8)=10
a(9)=a(8)+k, if k>0 then
a(9)=10+k
a(10)=10+2k.... and so on
so it happens that if k>0,each term after a(8) will be greater then 10, and in total
a9.a10.a11.a12.a13.a14-6 terms in total
if k<0 then,again
a(9)=a(8)+(-k)=10-k
a(10)=10-2k
a(11)=10-2k... and so on if k<0 then each term after a(8) will be less then 10, but each term before a(8) will be greater then 10, to prove
a(8)=a(7)+(-k). 10=a(7)-k. a(7)=10+k, and in similar way
a(6)=10+2k
a(5)=10+3k....and so on, as 2<=n<=14
a7,a6,a5,a4,a3,a2 will be greater than 10, notice that we do not include a1 an n>=2
and again in total we got six terms
so B is suff

Hey clock...

Brilliant Explanation....OA is indeed B

What do u think about the difficulty level of this question..????

hi Atul
thanks for kind words
as about difficulty, to me it is pretty hard and even unsolvable if you see this for the first time

clock60 wrote:hi Atul
thanks for kind words
as about difficulty, to me it is pretty hard and even unsolvable if you see this for the first time

Hi yeah i say this question is tricky...i picked up Op C first time because using both we can calculate the exact value of K, and i thought without getting exact value of K we can't say anything but we don't need the value of K...its a kind of C trap question when both Op's together seems an obvious answer...