C-01-Q151mediumsingle_mcqS={(1,5),(2,10),(3,15),(4,20)}S = \{(1, 5), (2, 10), (3, 15), (4, 20)\}S={(1,5),(2,10),(3,15),(4,20)} এর বিপরীত অন্বয় S−1=?S^{-1} = ?S−1=?a{(1,5),(2,10),(3,15),(4,20)}\{(1, 5), (2, 10), (3, 15), (4, 20)\}{(1,5),(2,10),(3,15),(4,20)}b