Which choice is more than 11 but less than 12? a) √115 b) √121 c) √136 d) √150

Let
x> the number

we know that
11²=121
12²=144

then
x² must be greater than 121  and less than 144

case a) √115
if x=√115
then
 x²=115> is not greater than 121

case b) √121 
if x=√121
then
 x²=121> is not greater than 121

case c) √136
if x=√136
then
 x²=136> is greater than 121 and is less than 144> is ok

case d) √150
if x=√150
then
 x²=150> is not less than 144

therefore

the answer is
√136