Cześć!
a)
[tex]\dfrac{7}{5}\cdot\dfrac{11}{4}\cdot\dfrac{1}{3}=\dfrac{7\cdot11\cdot1}{5\cdot4\cdot3}=\dfrac{77}{60}=\boxed{1\frac{17}{60}}\\[/tex]
b)
[tex]\dfrac{5}{2}\cdot\dfrac{9}{7}\cdot\dfrac{1}{7}=\dfrac{5\cdot9\cdot1}{2\cdot7\cdot7}=\boxed{\frac{45}{98}}\\[/tex]
