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?
1/2 + 1/3 = 5/6 That leaves 1/6, which is $3.21. Since 1/3 is spent on stamps, and 1/3 = 2x(1/6), then 2x$3.21 is spent on stamps. The answer is $6.42.
