The first three you should check off because the man lost less so the last few questions would be wrong
Answer: $15,000
As $35,000-$20,000=$15,000.
That's basically the profit he had made, or the return on his investment (ROI).
As he already had $20,000, he had "only" made $15,000.
4 days 10 days Cross Multiplication
---------- = ------------
7 mins x
4x = 7*10
4x = 70
x = 70/4
x = 17.5
17.5 minutes = x
A = {1, 2, 5, 6, 8}
{1} U {2, 5, 6, 8}
{2} U {1, 5, 6, 8}
{5} U {1, 2, 6, 8}
{6} U {1, 2, 5, 8}
{8} U {1, 2, 5, 6}
{1, 2} U {5, 6, 8}
{1, 5} U {2, 6, 8}
{1, 6} U {2, 5, 8}
{1, 8} U {2, 5, 6}
{1, 2, 5} U {6, 8}
{1, 2, 6} U {5, 8}
{1, 2, 8} U {5, 6}
{1, 5, 6} U {2, 8}
{1, 5, 8} U {2, 6}
{1, 6, 8} U {2, 5}
The answer is 15 distinct pairs of disjoint non-empty subsets.
