Answer :

iGreen
#2:

Square root of 135 is approximately 11.61895, so it's closest to 11 and 12.

#3:

Square root of 200 is approximately 14.1421356, so it's closest to 14 and 15.

#4:

Square root of 192 is approximately 13.8564065, so it's closest to 13 and 14.

#5:

Square root of 37 is approximately 6.08276253, so it's closest to 6 and 7.
√135 = 11,61895003862225, so two whole numbers closest to that are 11 and 12

√200 = 14,14213562373095, so two whole numbers closest to that are 14 and 15

√192 = 13,85640646055102, so two whole numbers closest to that are 13 and 14

√37 = 6,08276253029822, so two whole numbers closest to that are 6 and 7