Gavin, Harry and Isabel each earn the same monthly salary.

Each month,
Gavin saves 28% of his salary and spends the rest of his salary.
Harry spends 3/4 of his salary and saves the rest of his salary.
The amount of salary Isabel saves: the amount of salary she spends= 3:7
Work out who saves the most of their salary each month.

To determine who saves the most, we need to calculate the amount each person saves. Let's start with Gavin:

If Gavin saves 28% of his salary, he spends 100% - 28% = 72% of his salary.
Next, let's calculate Harry's spending and saving:

If Harry spends 3/4 of his salary, he saves 1 - 3/4 = 1/4 of his salary.
Now, let's find the ratio between Isabel's saving and spending:

The given ratio is 3:7, which simplifies to 3/10 for saving and 7/10 for spending.
Now we'll calculate their savings based on the given information:

Let's assume each person earns $100 to simplify the calculations.
For Gavin: 28% of $100 = $28 saved.
For Harry: 1/4 of $100 = $25 saved.
For Isabel: 3/10 of $100 = $30 saved.
Comparing their savings, we can see that Isabel saves the most with $30.

Therefore, Isabel saves the most of her salary each month.

Gavin: 28%

Harry: 25%
Isabel: 30%