189 and 40 have no factor in common and so the fraction cannot be reduced.
The reduced fraction for 40 over 100 is 2/5
The reduced fraction for 40 over 64 is 5/8
21/40 cannot be reduced.
The fraction 13/40 cannot be reduced any more.
The fraction 17/40 cannot be reduced any more.
2/5
40 over 12 reduced to its lowest term = 10/3 or 31/3
675/1000 = 27/40
21/40 cannot be reduced.
32 over 40 reduced is 4/5
The simplified fraction is: 920
5.25