Coversion problem F to C

#1

what is the term step here

#2

if you will see the example given in the question.
the inputs are:
0 (minimum F temperature)
100 (maximum F temperature)
20 (step : it the number by which the value of minimum F will increase until it attain a value greater than max F value )

so, the possible values of F temp is : 0,20,40,60,80,100
now, you are required to find the Celsius equivalent for these Fahrenheit temperature.

similarly, if step=30
possible F values will be: 0,30,60,90

hope this would clear your doubt.