`a, 6 5/12 : 2 3/4 + 11 1/4 . (1/3 - 1/5)`
`= 77/12 : 11/4 + 45/4 . 2/15`
`= 7/3 + 3/2`
`= 23/6`
`b, 5/16 : 0,25 - (2 1/4 - 0,6) . 10/11`
`= 5/16 : 1/4 - (9/4 - 3/5) . 10/11`
`= 5/4 - 33/20 . 10/11`
`= 5/4 - 3/2`
`=` $\frac{-1}{4}$
`c, 1,4 . 15/19 - (4/5 + 2/3) : 2 1/5`
`= 21/190 - 22/15 : 11/5`
`= 6/19 - 2/3`
`=` $\frac{-20}{57}$
`b, (-1,2) . (-3/24) + (0,4 - 1 4/15) : 1 2/3`
`= (-6/5) . (-3/24) + (2/5 - 19/15) : 5/3`
`= (-3/20) + (-13/25)`
`= -37/100`
`e, 1 13/15 . 0,75 - (11/20 + 25%)`
`= 28/15 . 3/4 - (11/20 + 1/4)`
`= 7/5 - 16/20`
`= 3/5`