Question

√x<4 A.20 B.12 C.2 D.-1 E.5. F. No solution

Answer 1

We know that for √x to be meaningful, we must have x ≥ 0.

If we square both sides of the inequality, we have
  x < 4²
  x < 16

Thus the whole solution is
  0 ≤ x < 16

The following choices are valid solutions to the inequality:
  B. 12
  C. 2
  E. 5