2012 CEMC Gauss (Grade 8) Problems/Problem 14

Problem

Half of the square root of a number is $1$ . The number is

$\text{ (A) }\ 2 \qquad\text{ (B) }\ 4 \qquad\text{ (C) }\ 8 \qquad\text{ (D) }\ 9 \qquad\text{ (E) }\ 16$

Let $x$ be the number that we are looking for. We then have:

$\frac{\sqrt{x}}{2} = 1$

Multiplying both sides by $2$ to get rid of the fraction, we have:

$\sqrt{x} = 2$

We can then square both sides to get rid of the square root, giving:

$x = \boxed {\textbf {(B) } 4}$

~anabel.disher