In 20 years charles will be 3 times as old as he is now. How old is he now? Let Charles's age be a today. We're given: a + 20 = 3a If we type this equation into our search engine, we get: a = 10 Let's check our work in our given equation: 10 + 20 ? 3(10) 30 = 30 <-- Checks out!