The relationship is 9/5 - 32, so approximately half of difference in Celsius (the -32 part won't be used in this case). Just looking at the answer choices you can pick B which is the only number near half of 25. The other answer choices are too far apart so no need to calculate.
This justifies what answer for what question? Q & A:
If C is the temperature in degrees Celsins and F is the temperature in degrees Fahrenheit, then the relationship between temperatures on the two scales is expressed by the equation 9C=5(F-32). In a weekly range of temperature recorded at a certain weather station differed by 25 degrees on the Fahrenheit scale, by how many degrees did the temperature extremes differ on the Celsius scale?
Options:
(A) a) 65/9
(B) b) 13
(C) c) 25
(D) d) 45
(E) e) 81
(B)