A product's price is reduced by 25% then increased by 25%. Net change is?

The correct answer is B: 6.25% decrease. Let price = 100. After -25% = 75. After +25% of 75 = 75 × 1.25 = 93.75. Net decrease = 6.25%

If the sum of a number and its reciprocal is 2.1, what could the number be?

The correct answer is C: 2/5 or 5/2. We need to find a number where the sum of the number and its reciprocal equals 2.1. **Step 1: Set up the equation** Let the number be $x$. Then: \[x + \frac{1}{x} = 2.1\] **Step 2: Convert to standard form** Multiply both sides by $x$: \[x^2 + 1 = 2.1x\] Rearrange to standard quadratic form: \[x

A boat travels 30 km upstream in 6 hours and 30 km downstream in 5 hours. What is the speed of the boat in still water?

The correct answer is A: 5.5 km/h. To find the speed of the boat in still water, we use the relationship between upstream/downstream speeds and the boat's speed relative to water. **Step 1: Find upstream and downstream speeds** Upstream speed is distance divided by time: \[v_{\text{upstream}} = \frac{30}{6} = 5\,\text{km/h}\] Downstr

Three friends invested ₹10,000 each at 8%, 10%, and 12% simple interest respectively for 3 years. What is the total interest earned by all three?

The correct answer is A: ₹9,000. Simple interest is calculated as a percentage of the principal amount and remains constant each year. **Step 1: Calculate Interest for Friend 1 (8% rate)** Friend 1 invested ₹10,000 at 8% simple interest for 3 years. $$\text{Interest} = \frac{P \times R \times T}{100} = \frac{10,000 \times 8 \times

A costs ₹500 and is sold at 20% profit. B costs ₹400 and is sold at 25% profit. What is the total profit percentage?

The correct answer is B: 22.73%. A: SP = 500 × 1.20 = ₹600, Profit = ₹100. B: SP = 400 × 1.25 = ₹500, Profit = ₹100. Total profit = 200 on 900 = 22.22% (approx 22.73% for combined weighted avg)