a) \(\frac{20}{11}\cdot\frac{33}{23}\cdot\frac{69}{180}=\frac{20\cdot33\cdot69}{11\cdot23\cdot180}=\frac{2^2\cdot5\cdot3\cdot11\cdot23\cdot3}{11\cdot23\cdot2^2\cdot3^2\cdot5}=1\)
b) \(\left(675,98+888,66+111,34\right)\cdot0,01=1675,98\cdot0,01=16,7598\)