Question: Mandy bought 3 packs of black shirts and 3 packs of yellow shirts for her tennis team. The black shirts come in packs of 5, and the yellow shirts come in packs of 2. How many shirts did Mandy buy in all?
Answer: The number of black shirts is 3 5 = 15. The number of yellow shirts is 3 2 = 6. Mandy bought 15 + 6 = 21 shirts. The answer is 21.

Question: On March 1st the sun sets at 6 PM. Every day after the sun sets 1.2 minutes later. It is 6:10 PM and 40 days after March 1st. How many minutes until the sun sets?
Answer: The sun will set 40 * 1.2 = 48 minutes later than it does on March 1st. That means the sun will set at 6:00 + 48 = 6:48 PM. So that means the time until sunset is 6:48 - 6:10 = 38 minutes. The answer is 38.

Question: Mason is three times younger than Sydney and Sydney is six years younger than Mason's father. If Mason is 20 years old, how old is his father?
Answer: Sydney is 20 * 3 = 60 years old. Mason's father is 60 + 6 = 66 years old. The answer is 66.

Question: Linda makes and sells necklaces at craft fairs. At her most recent fair she sold 4 necklaces and 8 rings for a total of $80. If each necklace costs $12, how much does each ring cost?
Answer:
Let's use r for the cost of each necklace. 4 * 12 + 8 * r = 80. 48 + 8 * r = 80. 8 * r = 80 - 48 = 32. 8r = 32. r = 4 dollars for each ring. The answer is 4.