#### Answer

$\frac{2}{13}$

#### Work Step by Step

Halloween cards to Mother’s Day cards.
As per Values given
20 million to 130 million
(20 million)/(130 million) = 20/130= (20 ÷10 )/(130 ÷10)= $\frac{2}{13}$
Ratio of Halloween cards to Mother’s Day cards is $\frac{2}{13}$