Out of the 20 students, 20 x 1 / 4 = 5 students stayed in the classroom. While 20 - 5 = 15 students went to the playground. Out of these 15 students, 15 x 1 / 3 = 5 are boys. Therefore, 15 - 5 = 10 girl students from this class are in the playground.
The answer: 10
Reverse engineering the question: There are 20 students in a class. Only one-fourth of the students stayed in the classroom while the rest went to the playground. Of those who went to the playground, one-third are boys. How many girls are there on the playground from this class?


Reasoning and answer: Three dozens of pebbles are equal to 3 x 12 = 36 pebbles. So, 36 / 4 = 9 friends received pebbles.
The answer: 9
What was the question?
Question: Janice gave all three dozens of pebbles from her trip to her friends. Each of her friends got 4 pebbles. How many friends received pebbles?


Taking the boxes of pans out of the total attic boxes shows that 26 boxes – 6 boxes of pans = 20 boxes are either decorations or teacups. Since half of these boxes are decorations, the other half must be made up of 20 boxes / 2 = 10 boxes of teacups. Each box of cups initially has 5 rows x 4 cups = 20 teacups inside. Samuel breaks cups each time he picks up a box, which means each box now contains 20 – 2 = 18 teacups. Therefore, there are 10 boxes * 18 teacups = 180 teacups left.
The answer: 180
Reverse engineering the question: Samuel is arranging his grandma’s teacups. They are stored in boxes and inside the boxes, they are stacked 5 rows high with 4 cups in each row. Of the 26 boxes in her attic, 6 of the boxes contain pans, half of the remaining boxes contain decorations, and the rest of the boxes contain her teacups. Samuel breaks 2 of the cups every time he picks up one of the boxes. By the time Samuel has taken all of the teacups out of the boxes, how many teacups are left?


Reasoning and answer: The candy bars cost 4 * 3 = 12 dimes. Sam has 19 - 12 = 7 dimes left. Sam has 6 - 1 = 5 quarters left. Sam has 7 * 10 + 5 * 25 = 195 cents left.
The answer: 195
What was the question?
Question: Sam has 19 dimes and 6 quarters. She buys 4 candy bars for 3 dimes each and 1 lollipop for 1 quarter. How much money, in cents, does she have left?


Since Zoe’s grandma gave her some money toward her trip, she needs to come up with $485 – $250 = $235. This means she must sell $235 / $1.25 / candy bar = 188 candy bars.
The answer: 188
Reverse engineering the question: Zoe wants to go on the field trip to Washington DC with her middle school this spring and the cost is $485. Her grandma gave her $250 toward her fees and she must earn the rest by selling candy bars. She makes $1.25 for every candy bar she sells. How many candy bars does Zoe need to sell to earn the money for the trip?


Today, Sheila’s piggy bank has $3000 + $7000 = $10000. Sheila will be saving for 4 years which is equivalent to 12 months / year * 4 years = 48 months. In 4 years, she will save $276 / month * 48 months = $13248. The piggy bank will have a total of $10,000 + $13,248 = $23248.
The answer: 23248
Reverse engineering the question:
Ever since she was a little girl, Sheila has dreamed of traveling the world. To help fund her dream, she bought a large piggy bank in December and started saving. By last week, she had saved $3,000. Pleased with her progress, she has decided to continue saving $276 per month, for 4 years. Today, Sheila’s family secretly added $7,000 into the piggy bank. At the end of 4 years, how much money will be in Sheila’s piggy bank?