At what temperature in $^oC$ is the density of water maximum?

Maximum density of $H_2O$ is at the temperature .......... $^\circ F$.

$Assertion :$ In a pressure cooker,water is brought to a boil. The cooker is then removed from the stove. Now,upon removing the lid of the pressure cooker,the water starts boiling again.
$Reason :$ The impurities in water bring down its boiling point.

In anomalous expansion of water, at what temperature is the density of water maximum?

Calculate the temperature which has the same numerical value on the Celsius and Fahrenheit scales.

The correct value of $0^{\circ}C$ on the Kelvin scale is ........... $K$.