Justin and Sabrina at Pine Grove Elementary have 50 pencils combined. Justin has 8 more than twice as many pencils as Sabrina. How many pencils does Sabrina have? Give the rationale and then the answer.
Let's think step by step. Let's say Sabrina has p number of pencils. If Justin has 8 more than twice as many pencils as Sabrina, he has 2 * p + 8 = 2p + 8. Together, Justin and Sabrina has p + (2p + 8) = 50. This is equal to 3p = 50 - 8. 3p = 42. The number of pencils that Sabrina has is p = 42 / 3. Sabrina has p = 14 pencils.. The answer is: 14.

Kalani has twenty candles in her bedroom, twice the number of candles in the living room. Donovan, her brother, brings in 20 more candles he bought from the candle shop. What's the total number of candles in the house? Give the rationale and then the answer.
Let's think step by step. If the number of candles in the bedroom is twice the number in the living room, there are 20 / 2 = 10 candles in the living room. When Donovan brings in 20 more candles, the total number of candles becomes 10 + 20 + 20 = 50.. The answer is: 50.

John volunteers at a shelter twice a month for 3 hours at a time. How many hours does he volunteer per year? Give the rationale and then the answer.
Let's think step by step. He volunteers 2 * 12 = 24 times a year. So he volunteers for 24 * 3 = 72 hours.. The answer is: 72.