So the difference between 45 and 10 is..
35 (omygad)
You have to divide 35/5 to get the average drop in the temperature PER HOUR, meaning 7 degrees per hour.
The Probability is 2/6 and 3/6. 2/6= 1/3 and 3/6=1/2 The ratio is 1/6
6.083 would be the answer