Answer:
0.3
Explanation:
1.00, or 100%. is the total of all probabilities
In the Venn diagram, we have the probabilities 0.2, 0.4 and 0.1;their sum will be 0.2+0.4+0.1 = 0.6+0.1 = 0.7.
We are left with 1.00-0.7 = 0.3 i.e the remaining probability of no toppings.