\[\boxed{\mathbf{1.}\mathbf{91}}\]
\[Число\ 420.\]
\[Первый\ способ.\]
\[6\%:\]
\[420 \cdot 0,06 = 4,2 \cdot 6 = 25,2.\]
\[12\%:\]
\[420 \cdot 0,12 = 50,4.\]
\[24\%:\]
\[420 \cdot 0,24 = 100,8.\]
\[30\%:\]
\[420 \cdot 0,3 = 42 \cdot 3 = 126.\]
\[60\%:\]
\[420 \cdot 0,6 = 42 \cdot 6 = 252.\]
\[Второй\ способ.\]
\[420 \cdot 6\ :100 = 25,2.\]
\[420 \cdot 12\ :100 = 50,4.\]
\[420 \cdot 24\ :100 = 100,8.\]
\[420 \cdot 30\ :100 = 126.\]
\[420 \cdot 60\ :100 = 252.\]