Answer:
There are 8 sets B that satisfy the conditions.
Step-by-step explanation:
We have to find the total subsets of S that have 1 as an element.
Subsets B with one element: {1}
Subsets with two elements: {1,4}, {1,6}, {1, 9}
Subsets with three elements: {1,4,6}, {1,4,9}{1,6,9}
Subsets with four elements: {1,4,6,9}
Therefore, B = {1, {1,4}, {1,6}, {1, 9}, {1,4,6}, {1,4,9}, {1,6,9}, {1,4,6,9}}
