Alisha has number cards with whole numbers on them. The probability of picking an even number is $\frac{2}{5}$. We need to find the ratio of even cards to odd cards.

1. Problem Description

Alisha has number cards with whole numbers on them. The probability of picking an even number is $\frac{2}{5}$. We need to find the ratio of even cards to odd cards.

2. Solution Steps

The probability of picking an even card is $\frac{2}{5}$. This means that for every 5 cards, 2 are even. Therefore, the probability of picking an odd card is $1 - \frac{2}{5} = \frac{3}{5}$.

If we have 5 cards total, 2 are even and 3 are odd. Thus the ratio of even to odd is $2:3$.

3. Final Answer

$2:3$