using range lookup in power bi

Hi i wanted to know ,, how could i use lookup in power bi

eg

if sheet1 in excel contained

column A                 COLUMN B          COLUMN C

roll number from     roll number to       CLASS   

1                                20                           A

20                               40                        B

40                                60                       C

and if wanted to know which roll no is in which class i would simple use lookup(3,a1:a30,c1:c30)

and i would get the desired answer

how do i replicate the same in power bi

thanks

pn, i have the sheet with rolls nos and class

and another sheet containg various different roll no ,, where i should i get the class 

thank you