A sum of ₹ 2236 is divided among A, B and C in such a way that A receives $25\%$ more than C and C receives $25\%$ less than B. What is A's share in the amount?
Aptitude
Percentage
Difficulty: Medium
Choose an option
-
A₹ 460
-
B₹ 780
-
C₹ 890
-
D₹ 1280
-
ENone of these
Answer
Correct Answer: ₹ 780
Explanation
### Concept & Strategy
When a total sum is distributed based on relative percentages, the most efficient method is converting the percentage relationships into a combined continuous ratio ($A : B : C$). Using fractions instead of decimals keeps the ratio integers clean and prevents rounding errors.
### Step-by-Step Solution
* **Given:**
Total Sum = ₹ $2236$.
$A = C + 25\%$ of $C = 1.25 \times C = \frac{5}{4} C$.
$C = B - 25\%$ of $B = 0.75 \times B = \frac{3}{4} B$.
* **Calculation / Deduction:**
First, establish the ratios:
From $A = \frac{5}{4} C$, we get the ratio $A : C = 5 : 4$.
From $C = \frac{3}{4} B$, we get the ratio $C : B = 3 : 4$.
To combine them into $A : C : B$, make the common term ($C$) equal.
Multiply $A : C$ by $3 \Rightarrow 15 : 12$.
Multiply $C : B$ by $4 \Rightarrow 12 : 16$.
Combined ratio $A : C : B = 15 : 12 : 16$.
So, $A : B : C = 15 : 16 : 12$.
Now, calculate the share values. Let the shares be $15x$, $16x$, and $12x$.
Total units = $15 + 16 + 12 = 43$ units.
$$43 \text{ units} = 2236$$
$$1 \text{ unit} = \frac{2236}{43} = 52$$
We need to find A's share:
A's share = $15 \text{ units} = 15 \times 52 = 780$.
### Exam Strategy & Shortcut
Use the Ratio Merging Method rapidly.
$A:C = 5:4$ and $C:B = 3:4$.
Write it like a block:
$A \quad C \quad B$
$5 \quad 4$
$\quad \quad 3 \quad 4$
Fill the empty spaces with the adjacent numbers:
$5 \quad 4 \quad 4$
$3 \quad 3 \quad 4$
Multiply vertically: $(5 \times 3) : (4 \times 3) : (4 \times 4) = 15 : 12 : 16$.
This grid method is much faster than algebraically balancing fractions under time pressure.
### Common Pitfall
A common trap is assuming that because A is $25\%$ *more* than C, and C is $25\%$ *less* than B, that A and B are equal. Percentages are relative to their base. A $25\%$ increase on a smaller base ($C$) does not equal a $25\%$ decrease from a larger base ($B$). The ratio method completely bypasses this logical trap.
### Final Answer
**Therefore, the correct answer is ₹ 780.**