Define a function that:

(1) takes a temperature as parameter

(2) returns Hot if the temperature is greater than 25

(3) returns Warm if the temperature is between 15 and 25, including 15 and 25.

(4) returns Cold if the temperature is less than 15.

If I called you function with foo(10) it would return Cold. 

foo(15) or foo(16) or foo(25) would all return Warm and foo(26) would return Hot.