will go for C.

for this type of pbality questions one should know that u dont have to solve this completely...... in DS look for option which gives hint for either both events happening or neither happening coz tat wont take much time to solve,which is 2) in this case......if u get solution u can plug in value for...

stmt 1) (n-2)(n-3)/n(n-1) = 15/28;n=8....suff


2) 2/n(n-1) = 1/28; n = 8...suff

hence D

given in the question a<y<z<b hence the distance b/w y and b (|y-b|) will always be greater than b/w z and b(|z-b|). so we can arrange them in the order.... |y-b| > |z-b|.....and .....|z-a| > |y-a|...(equ..a,b) now 1) |z-a|<|z-b|......hence |z-b| > |y-a|....so...|y-b| > |y-a|......suff. 2) |y-a|<|z-...

I have solved this one thru a number line.I want to know if the answer is D or not? I will post the solution if it is correct.

for C to be a correct answer as stated by mlaboda... the question has to be - Is (9)^(x(3-2x)) = 1? for this equation to hold true the power should be 0 as 9^0 = 1 so x(3-2x) = 0; and x=0,3/2 1) x is not 0; insuff,as x may be or may not be 3/2. 2) x is an integer;insuff,as x can be 0. taking both......

my answer will be D.
plz post OA.

yes it's correct...besides there is direct formula that number of permutations in circular arr. is (n-1)!.....i.e in this case y=11! and x=12!.hence x=12y.

however, i appreciate the way u have dun it. its better not to depend too much on direct formulas.