gmacforjyoab wrote:
LM wrote:
If n is an integer and \frac{1}{n+1}<\frac{1}{31}+\frac{1}{32}+\frac{1}{33}<\frac{1}{n}, then what is the value of n?
A) 9
B) 10
C) 11
D) 12
E) 13
A) 9
B) 10
C) 11
D) 12
E) 13
Did it on similar grounds as Bunuel
1/(n+1) < ( 1/31 + 1/32 + 1/33) < 1/n ...................... hence n+1 > a > n--------------------------------- eq 1
Substitute ( 1/31 + 1/32 + 1/33) to be 1/a
1/(n+1) < ( 1/a) < 1/n
1/a > 3/33 ( i.e 1/11) ... Hence a<11
from eq 1 --- n+1 >a>11 ................ n<a<11.. hence n <11
1/a < 3/31 ( or 1/10)..... hence a>10
from eq 1 --- n+1>a>10 .... hence n+1>10 ... n> 9
Ans n=10
I did it on the same grounds..
Answers is coming out to be 10.