Ten-year-old Zara Martinez had just inherited the most interesting problem in Riverside Town: her grandmother’s empty corner shop. Grandma Rosa had left her the keys, a notebook full of business wisdom, and one instruction: “Fill it with something the town truly needs.”

Zara stood in the dusty shop, her mind buzzing with possibilities. She could sell vintage clothes! Or start a pet grooming service! Maybe a robot repair shop! The ideas kept coming, but Zara remembered what Grandma Rosa always said: “Mija, having good ideas is easy. Knowing which ideas will actually work—that’s the real skill.”

That’s when Zara found Grandma Rosa’s secret weapon hidden in the old cash register: a worn piece of paper titled “The Great Idea Detective – 10 Questions to Find Winners.”

“Every successful business person needs to be a detective,” Grandma Rosa had written. “Before you fall in love with an idea, investigate it like a mystery. Ask these 10 questions and give each answer a score from 0 to 10.”

Zara pulled out her phone and opened a spreadsheet. Time to become an idea detective.

IDEA #1: VINTAGE CLOTHING BOUTIQUE

Zara started with her first love—vintage fashion. She worked through Grandma Rosa’s questions:

1. How much do people need it right now? Zara walked around town asking people about their shopping habits. “Clothes are important,” said Mrs. Kim at the coffee shop, “but I usually just buy them when my old ones wear out. It’s not urgent like food or medicine.” Score: 4 out of 10

2. How many people might want it? Zara surveyed the town. Riverside had 5,000 residents, but mostly families and older adults. Only about 200 teenagers and young adults seemed interested in vintage fashion. Score: 3 out of 10

3. How much might people pay? “I love vintage stuff,” said her cousin Elena, “but I can’t afford to spend much. Maybe $20 for something really special?” Score: 5 out of 10

4. How easy is it to find customers? Zara discovered that reaching vintage fashion lovers would require social media marketing, fashion events, and building an online presence—lots of work. Score: 4 out of 10

5. How much does it cost to make? Buying vintage inventory, renovating the shop, and creating displays would cost thousands of dollars. Score: 3 out of 10

6. How different is it from other things? Three towns over, there was already a successful vintage shop. Plus, online vintage shopping was everywhere. Score: 2 out of 10

7. How fast can you start selling it? Finding good vintage inventory, setting up the shop, and getting proper licenses would take months. Score: 3 out of 10

8. How much money do you need to start? Between inventory, renovations, and business setup, Zara estimated she’d need at least $8,000. Score: 2 out of 10

9. Can you sell more things to the same people? Once someone bought a vintage dress, they might not need another one for months or years. Score: 4 out of 10

10. Can it keep selling without much work? Vintage shops require constant hunting for new inventory, styling displays, and personal customer service. Score: 3 out of 10

VINTAGE BOUTIQUE TOTAL SCORE: 33 out of 100

“Oof,” Zara muttered, looking at the low score. “I love vintage fashion, but the numbers don’t lie. Let me try a different idea.”

IDEA #2: ROBOT REPAIR SHOP

1. How much do people need it right now? Zara discovered that many families in Riverside had broken electronics and gadgets they couldn’t afford to replace. “My tablet has been broken for six months,” said Mr. Chen. “I really need someone who can fix it!” Score: 8 out of 10

2. How many people might want it? Almost every household in Riverside had broken electronics. That was potentially thousands of customers. Score: 9 out of 10

3. How much might people pay? People were happy to pay $30-50 to fix a $200 device rather than buying a new one. Score: 7 out of 10

4. How easy is it to find customers? Word-of-mouth would spread quickly in a small town, and she could partner with local electronics stores. Score: 8 out of 10

5. How much does it cost to make? Basic repair tools and replacement parts were relatively inexpensive. Score: 7 out of 10

6. How different is it from other things? The nearest electronics repair shop was 45 minutes away. Nothing like this existed in Riverside. Score: 9 out of 10

7. How fast can you start selling it? Zara could start with basic repairs immediately and expand her skills over time. Score: 8 out of 10

8. How much money do you need to start? Basic tools and initial parts inventory would cost around $500. Score: 9 out of 10

9. Can you sell more things to the same people? Customers with multiple devices would return regularly. Plus, she could offer maintenance services. Score: 8 out of 10

10. Can it keep selling without much work? Once established, customers would keep coming with broken devices. The business could run relatively smoothly. Score: 7 out of 10

ROBOT REPAIR SHOP TOTAL SCORE: 80 out of 100

“Wow!” Zara exclaimed. “That’s a completely different story!”

But before making her final decision, Zara decided to test one more idea.

IDEA #3: MOBILE BIKE REPAIR SERVICE

1. How much do people need it right now? Zara noticed lots of people with broken bikes sitting in garages. “I’d love to ride my bike to work,” said Ms. Patterson, “but it’s been broken for a year. I just haven’t had time to take it somewhere.” Score: 7 out of 10

2. How many people might want it? Most families in Riverside owned bikes, and many were in need of repair. Score: 8 out of 10

3. How much might people pay? People were willing to pay $25-40 for convenient bike repairs at their home. Score: 6 out of 10

4. How easy is it to find customers? Zara could go door-to-door, partner with schools for bike safety events, and use social media. Score: 7 out of 10

5. How much does it cost to make? Bike repair tools and a mobile setup would be moderately expensive. Score: 6 out of 10

6. How different is it from other things? There was one bike shop in town, but no mobile service. The convenience factor made it unique. Score: 7 out of 10

7. How fast can you start selling it? Zara could learn basic bike repair skills and start service within weeks. Score: 7 out of 10

8. How much money do you need to start? Tools, trailer, and initial supplies would cost about $1,200. Score: 6 out of 10

9. Can you sell more things to the same people? Seasonal tune-ups, multiple bikes per family, and bike accessories offered repeat business. Score: 7 out of 10

10. Can it keep selling without much work? Once systems were in place, the service could run efficiently with scheduled appointments. Score: 6 out of 10

MOBILE BIKE REPAIR TOTAL SCORE: 67 out of 100

Zara stared at her three scores:

• Vintage Boutique: 33/100
• Robot Repair Shop: 80/100
• Mobile Bike Repair: 67/100

“The numbers are crystal clear,” she said, remembering Grandma Rosa’s scoring system. “80 out of 100 means the robot repair shop is a winner. 67 is pretty good for the bike service—maybe a future expansion. And 33… well, the vintage boutique would be a hobby, not a business.”

Three months later, “Zara’s Tech Fix” was the busiest corner shop in Riverside. Zara had learned everything she could about electronics repair, and customers lined up with broken phones, tablets, laptops, and gaming devices.

“How did you know this would work so well?” asked her friend Jake, watching Zara expertly replace a phone screen.

“I didn’t guess,” Zara replied, wiping her hands on her work apron. “I became a detective. My grandmother taught me that successful business isn’t about following your passion—it’s about following the evidence.”

“What evidence?”

Zara pointed to a framed copy of the 10-question framework hanging on her wall. “Before I fell in love with any idea, I investigated it. I asked the hard questions: Do people really need this? How many customers are there? Can I make money? How much will it cost to start?”

“But didn’t you really want to do the vintage clothing thing?”

“I did,” Zara admitted. “But wanting something and it being a good business are two different things. The vintage boutique scored 33 out of 100. This repair shop scored 80. The numbers don’t lie.”

Jake looked at the busy shop with new respect. “So you’re saying anyone can use this detective method?”

“Absolutely. Grandma Rosa’s framework works for any idea—lemonade stands, dog walking services, tech startups, anything. You just have to be honest about the scores and listen to what they tell you.”

That evening, as Zara counted her daily earnings, she opened Grandma Rosa’s notebook to the final page: “Remember, mija—the best business people aren’t the ones with the most creative ideas. They’re the ones who can tell which ideas will actually work. Be an idea detective, not just an idea dreamer.”

Zara smiled, looking around her thriving shop. She had learned the most valuable lesson in business: great detective work beats great imagination every time.

And in her desk drawer, she kept a list of future business ideas, each one ready to be investigated with her trusty 10-question framework. Because in business, as in detective work, the evidence always leads to the truth.