Multiple choice Given √(224) r = 13r, the value of radix r is 10 8 5 6 Reveal answer Fill a bubble to check yourself C Correct answer Explanation sqrt(224 base r) = 13 base r implies 224 base r = (13 base r)^2. (2*r^2 + 2*r + 4) = (r + 3)^2 = r^2 + 6r + 9. Solving r^2 - 4r - 5 = 0 gives (r-5)(r+1)=0. Since r > 0, r=5.