Maximum density of $H_2O$ is at the temperature

At what temperature are the centigrade (Celsius) and Fahrenheit readings the same?

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

$A$ certain liquid has a melting point of $-50^{\circ} C$ and a boiling point of $150^{\circ} C$. $A$ thermometer is designed with this liquid and its melting and boiling points are designated at $0^{\circ} L$ and $100^{\circ} L$. The melting and boiling points of water on this scale are

$A$ Celsius and a Fahrenheit thermometer are dipped in boiling water. The temperature of water is lowered until the Fahrenheit thermometer shows $140^{\circ}F$. What is the fall in temperature on the Celsius thermometer (in $^{\circ}C$)?

Explain different scales of temperature and write the equation for their relationship.