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very easy-1

Logic Level 1

When asked how old she was, Beth replied “In two years I will be twice as old as I was five years ago”. How old is she?

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Excel in math and science

Master concepts by solving fun, challenging problems.

It's hard to learn from lectures and videos

Learn more effectively through short, interactive explorations.

Used and loved by over 7 million people

Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.

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by Mohammad Khaza

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