11) If you divide my brother's age by 3 and then add 20 , you will get my age which is 31 .

To solve this age puzzle, we can start by letting your brother's age be represented as \( x \). According to the equation, dividing his age by 3 and adding 20 gives your age of 31. So we can write it as \( \frac{x}{3} + 20 = 31 \). If we isolate \( x \), we first subtract 20 from both sides, giving us \( \frac{x}{3} = 11 \). Then, multiplying both sides by 3, we find that your brother's age is \( 33 \). So, your brother is 33 years old! Isn't it amazing how mathematical relationships can reveal simple truths about our lives? This scenario is a classic example of linear equations in algebra, where such puzzles help us practice our problem-solving skills. Engaging with these types of problems can sharpen your ability to think critically and approach everyday challenges with a mathematical mindset!