Question: Miss Molly surveyed her class of 30 students about their favorite color. Half of the class answered green, one-third of the girls answered pink, and the rest of the class answered yellow. If there are 18 girls in the class, how many students like yellow best?
Answer: 30 / 2 = 15 students answered green. 18 / 3 = 6 girls answered pink. So, 15 + 6 = 21 students answered either green or pink. Therefore, 30 - 21 = 9 answered yellow. The answer is 9.

Question: Miriam spent 30 minutes doing laundry, 15 minutes cleaning the bathroom, a certain amount of time cleaning her room, and 40 minutes doing homework. If she spent a total of two hours on these tasks, how long, in minutes, did she spend cleaning her room?
Answer: There are 30 + 15 + 40 = 85 minutes accounted for. She spent 2 * 60 = 120 minutes. She spent 120 - 85 = 35 minutes cleaning her room. The answer is 35.

Question: Eden's mom is twice as old as Eden, who is twice as old as Devin. If Devin is 12 years old, what's the average age of the three?
Answer: If Devin is 12 years old, then Eden is 2 * 12 years = 24 years old. Since Eden's mom two times older than Eden, her age is 24 years * 2 = 48 years. In total, they have 48 years + 24 years + 12 years = 84 years. The average age for the three is 84 years / 3 people = 28 years / person. The answer is 28.

Question: On Rudolph's car trip across town, he traveled 2 more than 5 miles and encountered 3 less than 17 stop signs. How many stop signs per mile did Rudolph encounter on his trip across town?
Answer:
He traveled 2 more than 5 miles, or 5 + 2 = 7 miles. He encountered 3 less than 17 stop signs, or 17 - 3 = 14 stop signs. Thus, during his trip across town, Rudolph encountered 14 / 7 = 2 stop signs per mile. The answer is 2.