The fish tank in my Aunt's living room has 10 gallons of water. After 3 weeks, the water level is now at 7.25 gallons. How much water has evaporated?

What is the probably of getting heads when poing a coin and getting a number greater than or equal to 5 when rolling a single diea) 1/6b) 1/3c) 1/4d) 1/12