Hate to beat a dead horse, but I think the explanation that -x is the answer because "the question says x<0" is wrong. While -x is indeed the answer, the explanation is wrong and the logic faulty.

The real issue here is one of translation. You CANNOT rephrase sqrt(-x lxl) as sqrt(-(-x) lxl). The reason is because you have simply inserted a negative sign in front of the "x." The value of x will will still be a negative number.

A better translation is this: x = -y where y is a positive number.

Sqrt(-(-y) l-yl) gives you sqrt(y^2), which in turn gives you y. Since the equality we set up was x = -y, it is also true that y = -x. Thus, the answer is -x.

Some people have already said something similar in this thread, but they seemed to have been ignored so I thought I would reiterate.

Motherjane wrote: 1. OA is E.
h(100) = 2*4*6*8....*100
All prime numbers upto 50 is a factor of h(100).
For example the last prime number less than 50 is 47. 47 is a factor of 94 which is present in h(100). Any prime number greater than 50 is not a factor of h(100).

Hence, any prime number greater than 50 can be the factor of h(100)+1.

So answer is (E) greater than 40.

it asks for the smallest prime number.... the product of even numbers from 2 to 100 is divisible by 2, 3 or 5... so 'ill go with A