We have a question: Yoque borrowed money from her sister. She promised to pay it back in 11 months including an additional 10% of the money she borrowed. If she pays $15 per month, how much money did she borrow?
And an answer: 150
So how you got the answer?
In 11 months, Yoque will pay a total of $15 x 11 = $165. The amount $165 is 100% + 10% = 110% of the money she borrowed. So, 1% is equal to $165 / 110 = $1.50. Hence, Yoque borrowed $1.50 x 100 = $150.

We have a question: A snack machine accepts only quarters. Candy bars cost ¢25, each piece of chocolate costs ¢75, and a pack of juice costs ¢50. How many quarters are needed to buy three candy bars, two pieces of chocolate, and one pack of juice?
And an answer: 11
So how you got the answer?
Three candy bars cost ¢25 x 3 = ¢75. Two pieces of chocolate cost ¢75 x 2 = ¢150. So, the total amount needed to buy those is ¢75 + ¢150 + ¢50 = ¢275. Since a quarter is equal to ¢25, therefore ¢275 / ¢25 = 11 quarters are needed.

We have a question: A water tower that serves four neighborhoods around it holds 1200 barrels of water and is filled to the top each week. If one neighborhood uses 150 barrels of water in a week, the second neighborhood uses twice as many barrels of water as the first neighborhood in a week, and the third neighborhood uses one hundred more barrels of water than the second neighborhood in a week, how many barrels are left for the fourth neighborhood?
And an answer: 350
So how you got the answer?
The second neighborhood uses 150 * 2 = 300 barrels of water. The third neighborhood uses 300 + 100 = 400 barrels of water. The first, second, and third neighborhoods together use 150 + 300 + 400 = 850 barrels of water. Thus, the fourth neighborhood has 1200 - 850 = 350 barrels of water left for it to use.