Answer: <em>25%</em>
Step-by-step explanation:
<em>Let's take our given numbers</em>
<em>20% you win both checkers and chess against your friend</em>
<em>30% you win against your friend in chess</em>
<em>Now we take both probability's 20% and 30%</em>
<em>We are know working with a probability out of 200%</em>
<em>Let's add 20% and 30%</em>
<em>20%+30%=50%</em>
<em>Now 50% of 200% is </em>
<em>25%</em>
