Each week I save half my pocket money and I buy stamps for my collection with 1/3 of the pocket money. That leaves $3.21. How much do I spend on stamps?

x - .33x - .50x =3.21

x = 3.21/1.83
x = pocket money

PM -PM*1/2 -1/3 *PM=3.21

multiply both sides by 6
6PM-3PM-2PM=3.21*6
PM= 18.26

check that.

Joe. You erred above

x - .33x - .50x =3.21
x -.83x= 3.21
x=3.21/.17
x = pocket money

To find out how much you spend on stamps, we can follow these steps:

Step 1: Calculate the amount of pocket money after saving half.
Since you save half of your pocket money, it means you spend the other half. Therefore, the total amount of pocket money can be represented as 2 parts. Let's call this amount "x". So, after saving half, you would have x/2 remaining.

Step 2: Calculate the amount spent on stamps, which is 1/3 of the pocket money.
We know that x/2 will be the remaining amount of pocket money after saving half. So, the amount spent on stamps can be represented as (1/3) * (x/2).

According to the given information, the remaining amount of pocket money after spending on stamps is $3.21. So, we can set up the following equation:

x/2 - (1/3) * (x/2) = $3.21

Step 3: Solve the equation to find the value of x.
Simplifying the equation:
x/2 - (x/6) = $3.21
Common denominator = 6
3x/6 - x/6 = $3.21
2x/6 = $3.21
Simplifying further:
x/3 = $3.21

Now, multiply both sides of the equation by 3 to isolate x:
(3)(x/3) = (3)($3.21)
x = $9.63

Step 4: Calculate the amount spent on stamps.
We need to find 1/3 of the pocket money, which is (1/3) * $9.63.

Using a calculator:
(1/3) * $9.63 = $3.21

So, you spent $3.21 on stamps.