A cold water has a temperature of 10 'c. It stands in the room of the temperature 30 'c. After 10 min the temperature of the water rises to 15 'c. The temperature y 'c,

rises at a rate that is proportional to the difference of 30-y.

a) Setup a diffrential equation that describes this situation.

b)What will be the temperature of water after 20 min.

c)How fast does the temperature rise when it is 20 'c.

I would be grateful if somebody could help me.