A. 2 : 3 : 4
B. 6 : 7 : 8
C. 6 : 8 : 9
D. None of these
Originally, let the number of seats for Mathematics, Physics and Biology be 5z, 7z and 8z respectively
Number of increased seats are (140% of 5z), (150% of 7z) and (175% of 8z)
=> [ (140/100) x (5z) ] , [ (150/100) x (7z) ] and [ (175/100) x (8z) ]
=> 7z, (21z/2) and 14z
=> The required ratio = 7z : (21z/2) : 14z
=> 2 : 3 : 4