Which of the following is a rational number √32 square root of 81 square root of 90 or square root of 125
The square root of 81 is a rational number because it equals 9, which is a whole number.
To determine which of the given numbers is rational, we need to determine whether the square root of the number can be expressed as a fraction.
√32 cannot be expressed as a fraction, so it is not a rational number.
√81 can be simplified as 9, which is a whole number and can be expressed as a fraction (9/1). Therefore, √81 is a rational number.
√90 cannot be simplified as a whole number, so it is not a rational number.
√125 can be simplified as 5√5. Since √5 cannot be expressed as a fraction, √125 is not a rational number.
In summary, the only rational number among the given options is √81.