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Showing posts from October, 2024

Mastering Ratios & Proportion for Aptitude Tests!

Ratio and proportion is another building block for aptitude preparation. Here's a quick guide to sharpen your skills: 1️⃣ What is a Ratio? It's a way to compare quantities. E.g., if you have 2 apples and 3 oranges, the ratio is 2:3. 2️⃣ Scaling Ratios: Multiplying or dividing both terms by the same number keeps the ratio the same. E.g., if salaries in a 3:5 ratio get a 20% hike, the ratio remains 3:5. 3️⃣ Proportions: Two ratios are in proportion if they are equal. If a/b = c/d, then a × d = b × c. This is useful for solving word problems involving relationships between quantities. 4️⃣ Smart Problem-Solving with LCM: When comparing multiple ratios (e.g., a= 3:5 and b= 7:9), use the LCM to align terms for easier comparison. This simplifies complex problems into manageable steps! 5️⃣ Componendo and Dividendo: This is a powerful rule for ratio-based word problems: If a/b = c/d, then (a + b)/(a - b) = (c + d)/(c - d). Mastery of this can save time on tricky questions! 🔑 Quick...

Percentages: Concepts and Formulas for Placement Aptitude Tests

Percentages is one of the fundamental topics for placement aptitude tests. Here are some quick concepts and formulas to remember Any percentage can be expressed as a decimal by dividing the percentage figure by 100 Q: How will you express 5% in decimal? Sol: 5% = 5/100 = 0.05 2. Percentage change = (Absolute value change/ Original Qty) * 100 Q: Lara earned $1,500 last month and $1,200 this month. What is the percentage decrease in her earnings? Sol: Percentage change = (1,500 - 1,200) ÷ 1,500 × 100 = 20% 3. If the percentage increase is p%, then the new value is = Original value * ( 1 + p/100) Q: A shirt costs $40 and the price increased by 15%. What is the new price of the shirt? Sol : New price = 40 × (1 + 15/100) = 46 4. If the new value is “k” times the old value, then the percentage increase = (k-1)*100 Q:  A city’s population doubled in 10 years. What is the percentage increase? Sol:  Percentage increase = (2 - 1) × 100 = 100% 5. If an item’s value goes up by x%, th...