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100 Math Brainteasers

In January 1993, Sophie’s age equaled the sum of digits comprised in her birth year. What year was Sophie born in?

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AT THE TOY SHOP
Ben planned to buy 10 toy cars, but he found out he was $15 short.
So, he decided to buy only 8 cars instead — and still had $5 left.
If all the toy cars cost the same, how much does one car cost?

1. AT THE BOOKSTORE
Agatha was going to buy eight books, but it turned out she was $7 short. What she did was buy just seven books and was left with $5 to spare. How much did a single book cost if all the titles she was interested

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