Assuming the amount of money Germaine spent is 1 unit.
Germaine spent 1 unit.
Amanda spent 2 units.
The amount Germaine has left was $28 more than what she spent. Hence, Germaine is left with 1 unit + $28.
Amanda only have half of what Germaine is left.
Hence we split 1 unit + $28 into 2.
Not wanting to deal with half a unit, we let what Amanda had left as 1 unit.
Amanda is left 1 unit + $14
Germaine is left with 2 units + $28
Germaine spent 2 units.
Amanda spent 4 units.
Total we have 9 units + $42 which is the total sum they have initially.
9 units + $42 = $663
9 units = $621
1 unit = $69
(a) Amanda spent 4 units
4 units = $69 x 4 = $276

(b) Germaine has 4 units + $28 at first
$276 + $28 = $304