18 degrees F because
it dropped 12 degrees=10 hours
x degrees=15 hours
x is what you want to find out which is how many degrees it would drop in 15 hours.
12x15 then divided by 10 is 18.
55. If it says 12 more, you add 12 to 43 to get 55.
Answer:
x<1.5
explanation: move 4 to other side subtract it with 26.5 then divide it by 15
5/8 I believe. You can divide both by 9
The correct answer should be :
Option 3 : 
Hope this helps,
Davinia.