sud21 wrote:If b is an integer and b<10, x=1+ b/100. b=?
1). 1<=b<=3
2). The thousandth's digit of 10X^2 is equal to the tens's digit of x^2

[spoiler]IMO E?[/spoiler]
1) b = 1 or 2 or 3
so insuff.
2) the thousandths digit of 10x^2 is equal to ten's digit of x^2.
here i just took b = 1 to see how the value looks.
x = 1.01 => 10x^2 = 10.201 and x^2 = 01.0201
here i observed that if b is +ve and less than 10,then thousandths digit of 10x^2 can't be equal to ten's digit of x^2.

now let b = 0 then 10x^2 = 10.000 and x^2 = 01. this is valid. keep it.

now let b be -ve, after seeing the question i thought it is better to take b = -100
then 10x^2 = 00.000 and x^2 = 00. this is also valid.

so two values b=0 and b=-100 are satisfying the condition B. so insuff.

using both,
we still can't find the value of b. hence insuff.

user123321

x^2=(100+b)^2/100^2

Statement 1:

INSUFFICIENT

Statement 2:
for x<=0 10*x^2' thousand digit and x^2's tens digit are equal

Fails for x>0

INSUFFICIENT


Combining also no Single answer as you multiply by 10 for 1<=b<=3...the thousand digit and tens digit are different for 2 and 3 but same for 1

(E)
is the answer