Answer:
D. -8.1
Explanation:
Squares of natural numbers are
{1,4,9,16,25,36,49,64,81,...}, which are squares of {1,2,3,4,5,6,7,8,9,....}
As 65 lies between 64 and 81, square root of
65 lies between 8 and 9 Further, 8.1 2 = 65.61, and as 8.02 = 64, the square root of 65 lies between 8.0 and 8.1.