#### Explanation:

If the list price is $l$ then the actual selling price is $0.75 l$

If the cost price is $c$ then the selling price is $1.4 c$

$\therefore 0.75 l = 1.4 c$

or $\frac{3}{4} l = \frac{7}{5} c = \frac{7}{5} \cdot 30 = 7 \cdot 6 = 42$

$\therefore l = 42 \cdot \frac{4}{3} = 56$