√18
The closest perfect square to 18 are 16 and 25. Hence the closest integers to √18 are 4 and 5.
ii. √360
The closest perfect squares to 360 are 324 and 361. Hence the closest integers to √360 are 18 and 19.
-√195
The closest integers to 196 and 169. Hence the closest integers to -√195 are -14 and -13.
