Quantitative Aptitude - MCQ Practice Questions

Equivalent = 100 × (0.8 × 0.85 × 0.9) = 100 × 0.612 = 61.2. Discount = 38.8%

We need to find B's earnings when A and B together earn Rs. 12000 per month and A earns 40% more than B.

Step 1: Set up the relationship between A and B's earnings

Let B's monthly earnings = $x$ Rs.

Since A earns 40% more than B:

Step 2: Use the total earnings condition

A and B together earn Rs. 12000:

Step 3: Solve for B's earnings

Combine like terms:

Divide both sides by 2.40:

Step 4: Verify the answer

B's earnings = Rs. 5000

A's earnings = $1.40\times 5000=7000$

Total = $5000+7000=12000$ ✓

Answer: B's monthly earnings is Rs. 5000 (Option A)

Let CP = 100. MP = 140. After 25% discount, SP = 140 × 0.75 = 105. Profit = 5%.

Combined rate = $\frac{1}{20}$ + $\frac{1}{30}$ = $\frac{5}{60}$ = $\frac{1}{12}$. Time = 12 hours.

Speed = $\frac{150}{15}$ = 10 m/s = 10 × 3.6 = 36 km/h.

Net rate = $\frac{1}{12}$ - $\frac{1}{18}$ = $\frac{3}{36}$ - $\frac{2}{36}$ = $\frac{1}{36}$. Time = 36 hours.

Upstream speed = 8 km/h, Downstream speed = 12 km/h. Boat speed = (8+12)/2 = 10 km/h.

Simple interest is calculated as a percentage of the principal amount and remains constant throughout the investment period.

Step 1: [Identify the Given Values]

We need to extract all the information from the problem before applying the formula.

Step 2: [Apply the Simple Interest Formula]

The simple interest formula calculates the interest earned based on principal, rate, and time.

The simple interest on Rs. 8000 at 12% per annum for 2.5 years is Rs. 2400.

Let original price = 100, consumption = 100. New price = 125. For constant expenditure, consumption = $\frac{10000}{125}$ = 80. Decrease = 20%.

Let woman's salary = x. Man's salary = x + 500. x + x + 500 = 4500. x = 2000. Man earns Rs. 2500.

Combined rate = $\frac{1}{8}$ + $\frac{1}{12}$ = $\frac{5}{24}$. Time = $\frac{24}{5}$ = 4.8 days.

SP = 5000 + 20% of 5000 = 5000 + 1000 = 6000.

Final price = 100 × 0.9 × 0.8 × 0.7 = 50.4. Discount = 49.6%.

A = 6000(1.08)³ = 6000 × 1.2597 ≈ 7558.27. CI ≈ 1558.27 ≈ 1548.

A = P(1.1)³ = P × 1.331. 13310 = P × 1.331. P = 10000.

When a man sells at a loss, the selling price is less than the cost price. Here we use the loss percentage formula: $\text{Selling Price}=\text{Cost Price}\times \left(1-\frac{\text{Loss\%}}{100}\right)$

Step 1: Identify given information

Step 2: Apply the loss formula

When there is a loss of 15%, the selling price is 85% of the cost price:

Step 3: Calculate the selling price

Answer: The selling price is Rs. 15300 (Option D)

Downstream speed = 15 km/h. Upstream speed = 10 km/h. Stream speed = (15-10)/2 = 2.5 km/h.

Total work = 15 × 20 = 300 worker-days. Workers needed = $\frac{300}{12}$ = 25.

Let CP = 100. MP = 150. For 25% profit, SP = 125. Discount = (150-125)/150 × 100 = 16.67%.

SI = (20000 × 10 × 2)/100 = 4000. CI = 20000(1.1)² - 20000 = 24200 - 20000 = 4200. Difference = 200.