Q: Kurt's old refrigerator cost $0.85 a day in electricity. He recently bought a new energy-efficient refrigerator that only cost $0.45 a day in electricity. How much money does Kurt save in a 30-day month with his new refrigerator?
A: The old refrigerator costs $0.85 a day so for 30 days it costs .85 * 30 = $25.50. The new refrigerator costs $0.45 a day so for 30 days it costs .45 * 30 = $13.50. Over 30 days, Kurt saves 25.50 - 13.50 = $12.00 a month with his new refrigerator. The answer is 12.

Q: In a guessing game, Hajar's score is 24 points. The difference in the scores between Hajar and Farah's score in the game is 21. What is the sum of their scores, assuming Farah's score is higher than Hajar's?
A: If the difference in scores between Farah and Hajar in the game is 21 points, and Hajar's score is 24, then Farah has a score of 21 + 24 = 45 points. The overall score in the game is 45 + 24 = 69. The answer is 69.

Q: Marie has 4 notebooks with 20 stamps each. She also has two binders with 50 stamps each. If she decides to only keep 1/4 of the stamps, how many stamps can she give away?
A:
Marie has 4 x 20 = 80 stamps from her notebooks. And she has 2 x 50 = 100 stamps from her binders. So she has a total of 80 + 100 = 180 stamps. Marie decided to keep 180 x 1 / 4 = 45 stamps only. Therefore, she can give away 180 - 45 = 135 stamps. The answer is 135.