Quantitative Aptitude - MCQ Practice Questions

SI = (5000 × 12 × 2.5)/100 = 1500. Amount = 5000 + 1500 = 6500

SI = (20000 × 8 × 5)/100 = 8000. Amount = 20000 + 8000 = 28000

Using SI = (P × R × T)/100; 800 = (4000 × R × 2)/100; R = 10% p.a.

Sum of 5 friends = 5 × 24 = 120. Sum of 4 friends = 4 × 22 = 88. Age of friend who left = 120 - 88 = 32 years.

Total cost = (10 × 50) + (15 × 40) = 500 + 600 = 1100. Total items = 25. Average = $\frac{1100}{25}$ = ₹44.

Sum of 6 numbers = 6 × 18 = 108. Sum of 3 numbers = 3 × 24 = 72. Total sum = 180. Total numbers = 9. New average = $\frac{180}{9}$ = 20.

Total distance = 120 + 180 = 300 km. Total time = 2 + 3 = 5 hours. Average speed = $\frac{300}{5}$ = 60 km/h.

Sum needed for average 85 in 4 subjects = 4 × 85 = 340. Sum of 3 scores = 75 + 82 + 88 = 245. Fourth subject score = 340 - 245 = 95.

To find C's weight, use the definition of average: the sum of all values divided by the count equals the average.

Step 1: Set up the average formula

The average weight of A, B, and C is 70 kg, so:

Step 2: Express the sum of weights

Multiply both sides by 3 to find the total weight:

Step 3: Substitute known values

We know A = 75 kg and B = 68 kg. Substitute into the equation:

Step 4: Solve for C's weight

**Answer: C's weight is $67\text{kg}$ (Option C)**

To find the new average, we must first calculate the total score change when a student leaves and a new student joins.

Step 1: Find the Total Score of Original 5 Students

The average of 5 students is 78, so we multiply the average by the number of students to get the total.

Step 2: Calculate the New Total Score

When a student scoring 68 leaves, we subtract 68. When a new student scoring 88 joins, we add 88.

Step 3: Find the New Average

The number of students remains 5. Divide the new total by 5 to get the new average.

The new average is 82.

Answer: (B) 82

Sum of 4 numbers = 35 × 4 = 140. Sum of 3 numbers = 28 + 36 + 42 = 106. Fourth number = 140 - 106 = 34.

Average speed is the total distance traveled divided by the total time taken, calculated as $\text{Average Speed}=\frac{\text{Total Distance}}{\text{Total Time}}$.

Step 1: Calculate total distance

The train travels in two segments:

Step 2: Calculate total time

The train travels for two different periods:

Step 3: Apply the average speed formula

Step 4: Simplify the division

Total distance traveled:

200+150=350 km

Total time taken:

4+2.5=6.5 hours

Average speed:

Average Speed=

Total Time

Total Distance

​

=

6.5

350

​

=

13

700

​

≈53.85 km/h

Therefore, the average speed is approximately 53.85 km/h.

**Answer: The average speed is approximately $53.85\text{ km/h}$ (Option C)**

Rate of worker 1 = $\frac{1}{8}$, worker 2 = $\frac{1}{12}$. Combined rate = $\frac{1}{8}$ + $\frac{1}{12}$ = (3+2)/24 = $\frac{5}{24}$. Time = $\frac{24}{5}$ = 4.8 days.

Total height of 5 = 165 × 5 = 825 cm. After adding 180 cm: 825 + 180 = 1005 cm. New average = $\frac{1005}{6}$ = 167.5 cm.

Total income of 4 = 45000 × 4 = 180000. After 5th employee: 180000 + 55000 = 235000. New average = $\frac{235000}{5}$ = 47000.

Sum of 5 numbers = 48 × 5 = 240. Sum of 4 numbers = 40 + 45 + 50 + 55 = 190. Fifth number = 240 - 190 = 50.

Profit per unit = $\frac{2500}{50}$ = 50. This remains constant regardless of quantity. Average profit per unit = ₹50.

Profit per article = 120 - 80 = ₹40. Profit percentage = ($\frac{40}{80}$) × 100 = 50%. This remains constant for any number of articles, so average profit = 50%.

SI = (P × R × T) / 100 = (15,000 × 12 × 2) / 100 = ₹3,600. Average per year = 3,$\frac{600}{2}$ = ₹1,800.

[The key to solving this problem is finding the total revenue from all items, subtracting the revenue from the 2 discounted items, and then dividing by the remaining quantity.]

Step 1: Find the Total Selling Price of All 8 Items

The average selling price is given as ₹250 for 8 items, so we multiply to find the total.

Step 2: Calculate the Selling Price of the 2 Items Sold at ₹180 Each

Two items were sold at ₹180 each, so we find their combined revenue.

Step 3: Find the Total Selling Price of Remaining 6 Items

Subtract the revenue from the 2 discounted items from the total revenue.

Step 4: Calculate the Average Price of the Remaining 6 Items

Divide the total price of 6 items by the quantity.

The average price of the remaining 6 items is ₹273.33.

The answer is (A) ₹273.33