Money Matters: Outsmarting Frauds and Crunching
Numbers
Welcome, financial detectives! Today, you’re stepping into the shadowy world of
scams, schemes, and surprising costs. Along the way, you’ll solve puzzles,
calculate risks, and uncover secrets that even the cleverest fraudsters don’t want
you to know. Let’s sharpen your math skills and protect your wallet—one
problem at a time.
1: Scams and Percentages
1. A scammer offers a "miracle investment" promising a 500% return in one
week. If you invest $100, how much money are they claiming you’ll earn? Why is
this offer suspicious?
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2. A lottery email claims you’ve won $10,000 but asks for a “processing fee” of
15%. How much would you need to pay upfront, and how much do you actually
get?
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3. An online store advertises a “75% OFF MEGA SALE” on a product originally
priced at $80. They also add 8% sales tax at checkout. What is the final price?
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4. Statistics reveal that 25% of phishing scam victims lose over $1,000. In a town
of 7500 people, how many might suffer this loss?
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2: Loans, Credits, and Ratios
5. A payday lender offers a $500 loan with 10% interest per month. If you wait
three months to repay, how much will you owe?
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6. A friend suggests borrowing $1,000 and repaying in 10 monthly installments
of $120. Compare this to repaying the $1,000 without interest. How much extra
do you pay?
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7. If $250 of your $2,000 monthly salary goes to taxes, what is the ratio of taxed
income to total income? Express this in its simplest form.
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8. Compare two loan options: (1) A car loan at a 6% annual interest rate, or (2) a
credit card charging 2% monthly interest. Which is more expensive over a year
for a $2,000 loan?
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3: Taxes and Conversion Rates
9. A product costs $150 in a tax-free country. In your country, there’s a 7%
additional cost tax. How much more expensive is the product with tax?
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10. If you earn $3,000 a month and pay 12% in taxes, what is your take-home
salary?
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11. You’re traveling abroad and need 1,000 euros. The exchange rate is 1 euro =
36.3 baht. How many baht will you need?
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12. On returning, you exchange leftover 300 euros at 1 euro = 1.1 dollars. How
many dollars will you receive?
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4: Statistics and Probability
13. Reports suggest 1 in 10 people fall for scams. If a city has 5,000 residents,
how many are likely to become victims?
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14. You’re comparing two lotteries: (A) a 1 in 1,000 chance to win $5,000 or (B) a
1 in 2,000 chance to win $10,000. Which lottery offers a better expected value?
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15. A scammer sends fake emails to 4,000 people, and 3% respond. How many
victims fall for the scam?
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5: Fun Scenarios with Frauds and Finance
16. A retailer offers a $1,200 smartphone in 12 installments of $110 each. How
much more do you pay compared to the original price?
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17. A fake charity promises to “double your impact” for every $50 donation. If
300 people each donate $50, how much does the scammer collect?
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18. A product is advertised as “$20 plus 20% VAT” at one store and $23.99 flat at
another. Which option is cheaper, and by how much?
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19. A new app promises a “guaranteed” monthly return of 8%. If you invest
$2,000, how much will you have after one year, assuming this rate compounds
monthly?
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20. A scammer offers “10% cashback” on purchases over $100 but charges a $15
“processing fee.” How much do you save—or lose—if you spend exactly $100?
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Extra Challenge
Detectives, these dilemmas are designed to push your limits. Each question tests
your ability to analyze, calculate, and outsmart financial traps. Are you ready to
solve the toughest cases yet? Good luck!
1. Hidden Costs
A loan company advertises “zero interest loans.” However, they charge a 13%
“processing fee” on the borrowed amount. If you take a $2,000 loan, how much
do you really receive, and how much do you pay back?
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2. Probability and Trust
A survey shows that 8 out of 10 people trust online shopping platforms without
checking for reviews or security badges. If a group of 250 people shops online,
how many are at risk of fraud due to this behavior?
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3. Comparing Payment Plans
You’re buying a $1,500 laptop. Option A offers a 10% upfront discount but adds
12% sales tax to the remaining amount. Option B charges the full price but waives
the sales tax. Which option costs less, and by how much?
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4. Deceptive Investments
An “investment opportunity” claims a guaranteed monthly return of 5%. You
invest $5,000. How much will you have after one year if the interest compounds
monthly? Is this deal realistic? Why or why not?
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5. Tricky Advertisements
A store promotes a "buy one, get one 50% off" deal on $40 items. Another store
offers a “flat 30% off” deal on the same item. If you want to buy two items, which
store provides a better deal, and how much do you save?
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6. Taxation Mystery
A worker’s salary is taxed as follows: 10% for the first $1,000, 15% for the next
$2,000, and 20% for the remaining amount. If their monthly salary is $5,000,
how much tax do they pay in total, and what’s their take-home pay?
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7. Scam Alerts and Ratios
A scammer promises to triple your money if you invest $500. If 300 people fall
for this scam, what’s the total amount scammed? What is the ratio of the
scammer's gain to the victims’ loss?
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8. Risk and Rewards
A lottery offers a 1 in 5,000 chance to win $50,000, and tickets cost $15. What is
the expected value of one ticket? Is this a smart investment?
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9. Salary Scenarios
Two friends earn $4,000 each. Alex spends 30% of their salary on essentials and
saves the rest, while Blake spends 50% and saves the rest. Who saves more, and
by how much?
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10. Loan or Installments?
You need $10,000 for tuition. Option A is a 5-year loan at 8% annual interest.
Option B lets you pay in 60 monthly installments of $220 each. Compare the
total payments for each option and decide which is better.
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The Grandmaster’s Challenges
Welcome to the pinnacle of your mathematical journey! These five problems
represent the most complex and thought-provoking financial scenarios, designed
to test your analytical prowess. Solve these mysteries with precision and strategy.
Each step brings you closer to mastering the art of financial and mathematical
analysis. Good luck!
1. The Currency Puzzle
You are traveling between three countries: Zephyria (currency: Zephyr -ZP),
Drakonia (currency: Drak - DK), and Luminara (currency: Lumens - LM)
exchange rates are:
- 1 unit of ZP = 2.5 units of DK
- 1 unit of DK = 0.8 units of LM
- 1 unit of LM = 0.6 units of ZP
Starting with 1,000 units of ZP, exchange your money through DK and LM, and
then convert the remaining sum back to ZP. How much money remains?
Calculate the percentage gain or loss.
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2. The Tax Conundrum
A country’s income tax is progressive:
- 10% on the first $10,000
- 20% on the next $20,000
- 30% on income above $30,000
If an individual earning $50,000 annually claims $5,000 in deductions (which
reduce taxable income dollar-for-dollar), how much tax do they save compared to
no deductions?
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