The cost of 5 kgs of apples is ₹ 450. The cost of 12 dozen mangoes is ₹ 4,320 and the cost of 4 kgs of oranges is ₹ 240. What is the total cost of 8 kg of apples, 8 dozens of mangoes and 8 kg of oranges? [MAT—2012]
Aptitude
Unitary Method
Difficulty: Easy
Choose an option
-
A₹ 4,020
-
B₹ 4,080
-
C₹ 4,050
-
DOther than those given as options
Answer
Correct Answer: ₹ 4,080
Explanation
### Concept & Unitary Method
Calculate the unit price for each commodity individually, then multiply by the requested quantity (8 units for each) to find the final aggregated cost.
$$ \text{Cost} = (\text{Unit Price}) \times (\text{Quantity}) $$
### Step-by-Step Solution
* **Apples:**
* Cost of 5 kg = ₹ 450
* Cost of 1 kg = $\frac{450}{5} = ₹ 90$
* Cost of 8 kg = $8 \times 90 = ₹ 720$
* **Mangoes:**
* Cost of 12 dozen = ₹ 4320
* Cost of 1 dozen = $\frac{4320}{12} = ₹ 360$
* Cost of 8 dozen = $8 \times 360 = ₹ 2880$
* **Oranges:**
* Cost of 4 kg = ₹ 240
* Cost of 1 kg = $\frac{240}{4} = ₹ 60$
* Cost of 8 kg = $8 \times 60 = ₹ 480$
* **Total Cost:**
* Total = $720 + 2880 + 480$
* Total = $3600 + 480 = 4080$.
### Exam Strategy & Shortcut
Instead of finding the unit price, use fractions to directly find the cost for 8 units:
Apples: $\frac{8}{5} \times 450 = 8 \times 90 = 720$.
Mangoes: $\frac{8}{12} \times 4320 = \frac{2}{3} \times 4320 = 2 \times 1440 = 2880$.
Oranges: $\frac{8}{4} \times 240 = 2 \times 240 = 480$.
Sum = $720 + 2880 + 480 = 4080$.
### Common Pitfall
Be careful not to convert "dozens of mangoes" into individual mangoes. The initial price and the final requested price are both in "dozens", so treat a "dozen" as the base unit.
### Final Answer
Therefore, the correct answer is **₹ 4,080**.