a) 5/9*3/12*3/10=15/108*3/10=3/36*1/2=3/72=1/24 b) 5/16:12/5*8/25=5/16*5/12*8/25=25/192*8/25=1/48*2/1=2/48=1/24 c) 10/21*1/5:16/7=10/21*1/5*7/16=2/21*1/1*7/16=2/21*7/16=1/3*1/8=1/24 d) 7/18*15/24*6/35=7/6*5/24*6/35=35/144*6/35=1/24*1/1=1/24
[latex]cfrac{5}{9}*cfrac{3}{12}*cfrac{3}{10}=cfrac{1}{1}*cfrac{1}{12}*cfrac{1}{2}=cfrac{1}{24}\ \ \ cfrac{5}{16}:cfrac{12}{5}*cfrac{8}{25}=cfrac{5}{16}*cfrac{5}{12}*cfrac{8}{25}=cfrac{1}{2}*cfrac{1}{12}*cfrac{1}{1}=cfrac{1}{24}\ \ \ cfrac{10}{21}*cfrac{1}{5}:cfrac{16}{7}=cfrac{2}{21}*cfrac{1}{1}*cfrac{7}{16}=cfrac{1}{3}*cfrac{1}{1}*cfrac{1}{8}=cfrac{1}{24}\ [/latex] [latex]cfrac{7}{18}*cfrac{15}{24}*cfrac{6}{35}=cfrac{1}{3}*cfrac{3}{24}*cfrac{1}{1}=cfrac{1}{1}*cfrac{1}{24}*cfrac{1}{1}=cfrac{1}{24}[/latex]