Converting each of the given fractions into decimal form, we get,5/6 = 0.838/15 = 0.532/3 = 0.663/4 = 0.754/5 = 0.86/7 = 0.85Clearly, 0.85 does not lie between 0.83 and 0.53Hence the required fraction is 6/7.
Given expression = (11.98)² + (0.02)² + 11.98 x x.For the given expression to be a perfect square, we must have11.98 x x = 2 x 11.98 x 0.02 or x = 0.04