Question: Samanta is planning a party for her friend Marta. She decided to raise some money among the guests she invited, to buy Marta a gift. Every participant gave Samanta $5 for this purpose and she herself put in $10. The gift cost was lower than expected, so there was $15 leftover. What was the price of the gift, if there were 12 guests invited?
Answer: From all the guests Samanta got $5 / guest * 12 guests = $60. Including money Samanta put herself, she had $60 + $10 = $70. The cost of the gift was $70 - $15 = $55. The answer is 55.

Question: Ginger is weaving mats out of colored straw. Each mat takes 20 red straws, 30 orange straws, and half as many green straws as orange straws. How many straws does she need to make 10 mats?
Answer: First find the number of green straws each mat needs: 30 orange straws / 2 orange straws / green straw = 15 green straws. Then find the total number of straws in each mat: 15 straws + 20 straws + 30 straws = 65 straws. Then multiply that number by the number of mats to find the total number of straws Ginger needs: 65 straws / mat * 10 mats = 650 straws. The answer is 650.

Question: In a rice field, you can get a total of 20 sacks of rice every harvest. If the yield increases by twenty percent after every harvest, what is the total number of sacks of rice you can get after the first and second harvest?
Answer: There were 20 x 0.20 = 4 sacks of rice increase after the first harvest. So the total sack of rice that you can get on the next harvest 20 + 4 = 24. Therefore the total number of sacks of rice you will get on the first and second harvest is 20 + 24 = 44. The answer is 44.

Question: The average score on last week's Spanish test was 90. Marco scored 10% less than the average test score and Margaret received 5 more points than Marco. What score did Margaret receive on her test?
Answer:
The average test score was 90 and Marco scored 10% less so 90 * .10 = 9 points lower. The average test score was 90 and Marco scored 9 points less so his test score was 90 - 9 = 81. Margret received 5 more points than Marco whose test score was 81 so she made 5 + 81 = 86 on her test. The answer is 86.