Its 40 you basically add it kus if it gets colder than the temperature must of been higher so you add
8. 8 is greater than 3 and is all the way to theeft. if it was to the right, you'd need more info
The answer would be 901 because they said what is the least number they would need to read and their goal is MORE than 900. The amount of books that they already had is useless information (Ignore). They love giving trick questions. :)
y=10+x(0.5)
This is the way of writing that equation.
