In an innings of a cricket match, three players A, B and C scored a total of 361 runs. If the ratio of the number of runs scored by A to that scored by B and also number of runs scored by B to that scored by C be 3 : 2, the number of runs scored by A was
Aptitude
Ratio and Proportion
Difficulty: Medium
Choose an option
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A161
-
B171
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C181
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D185
Answer
Correct Answer: 171
Explanation
### Concept & Combining Identical Ratios
Similar to standard ratio combination, when $A:B$ and $B:C$ are given the exact same proportion, we scale them to match the common term (B) to create a unified $A:B:C$ ratio to distribute the total.
$$ \text{Combined Ratio: } (A \times B_{new}) : (B \times B_{new}) : (C \times C_{new}) $$
### Step-by-Step Solution
1. **Identify the individual ratios:**
$A : B = 3 : 2$
$B : C = 3 : 2$
2. **Equate the common term (B):**
The values for B in the two ratios are 2 and 3. Their LCM is 6.
Scale the first ratio by multiplying by 3: $A : B = (3 \times 3) : (2 \times 3) = 9 : 6$
Scale the second ratio by multiplying by 2: $B : C = (3 \times 2) : (2 \times 2) = 6 : 4$
3. **Form the combined ratio:**
$A : B : C = 9 : 6 : 4$
4. **Calculate A's runs:**
Total ratio parts = $9 + 6 + 4 = 19$.
Total runs scored = 361.
A's runs = $\frac{9}{19} \times 361$
$361 \div 19 = 19$ (Note: $19^2 = 361$)
A's runs = $9 \times 19 = 171$
### Exam Strategy & Shortcut
Recognize that 361 is the square of 19 ($19 \times 19$). When you see the sum of the ratio parts is 19 ($9+6+4$), the math instantly simplifies. The multiplier is exactly 19. A's share is just $9 \times 19 = 171$. Knowing squares up to 25 gives you a massive speed advantage in aptitude tests.
### Common Pitfall
A common misinterpretation of the phrasing "and also" is assuming all three scored in a $3:2:1$ or similar sequence, rather than treating them as two separate $3:2$ overlapping relationships.
### Final Answer
Therefore, the correct answer is **171**.