After 1 year Jim has gained $80 * 0.15 = $12. Therefore, after 1 year his portfolio has grown to $80 + $12 = $92. He then adds $28 to this total, so his new portfolio total is $92 + $28 = $120 at the beginning of year 2. Next, this total grows by 10%, so he gains $120 * 0.10 = $12 across year 2. Thus, after year 2, his portfolio is worth $120 + $12 = $132.
The answer: 132
Reverse engineering the question: Jim starts with $80 in his investment portfolio. After 1 year it grows by 15%. He then adds another $28 to his portfolio. After 1 more year the combined portfolio grows by 10%. What is his final portfolio worth after 2 years from when he started?

He has 60 - 20 = 40 kilograms of mangoes left after selling them to the market. Colby sold 1 / 2 x 40 = 20 kilograms of mangoes to the community. Therefore, Colby still has 20x8 = 160 pieces of mangoes.
The answer: 160
Reverse engineering the question: Colby harvested his mango trees, the total mangoes he harvested is 60 kilograms. He sold 20 kilograms to the market and sold the remaining half to his community. If each kilogram contains 8 mangoes, how many mangoes does he still have?

If Kevin has 40 counters, and Reina has three, the number of counters Kevin has, Reina has 3 * 40 = 120 counters. Reina also has four times the number of marbles that Kevin has, meaning he has 4 * 50 = 200 marbles. In total, Reina has 120 counters + 200 marbles = 320 items.
The answer: 320
Reverse engineering the question: Reina has three times the number of counters and four times the number of marbles as Kevin. If Kevin has 40 counters and 50 marbles, calculate the number of counters and marbles that Reina has?

Anna bought 3 packs of chewing gum that were $1 each for a total of 3 * 1 = $3. Anna bought 5 chocolate bars that were $1 each for a total of 5 * 1 = $5. Anna bought 2 large candy canes that were $.50 each for a total of 2 * .50 = $1. The total amount spent was $3 + $5 + $1 = $9.00. Anna had $10 to start and spent $9.00 so she had $10 - $9.00 = $1.00 left.
The answer: 1
Reverse engineering the question:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
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Anna's mom gave her $10.00 to buy anything she wanted from the candy store. Anna bought 3 packs of chewing gum for $1.00 each, 5 chocolate bars at $1 each and 2 large candy canes for $0.50 each. How much money did Anna have left?