4. Henry has $3.60 more than Helen. Helen has twice as much as Bill. If all three have $19.85 all together, how much money does Helen have?

Henry = a

Bill = b
Helen = h
a = h + 3.60
h = 2 b
a + b + h = 19.85
so from the first two
a = 2 b + 3.60
so
(2 b + 3.60) + b + 2 b = 19.85
5 b + 3.60 = 19.85
5 b = 16.25
b = 3.25
h= 2 b = $6.50