Question

$<var>1-\frac{1}{3} \cdot \left \{ {{1-\frac{1}{3} \cdot [1 - \frac{1}{3} \cdot (1 - \frac{1}{4} ) ] </var>$}

Answer 1

1-1/3{1-1/3.[1-1/3.(1-1/4)]}=
1-1/3[1-1/3.(1-1/3.3/4)=
1-1/3.[1-1/3.(1-1/4)]=
1-1/3.(1-1/3.3/4)=
1-1/3.(1-1/4)=
1-1/3.3/4=
1-1/4=3/4