A bag contains three types of coins — 1-rupee coins, 50 p-coins and 25 p-coins totalling 175 coins. If the total value of the coins of each kind be the same, the total amount in the bag is
Aptitude
Simplification
Difficulty: Medium
Choose an option
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A₹ 75
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B₹ 126
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C₹ 175
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D₹ 300
Answer
Correct Answer: ₹ 75
Explanation
### Concept & Logic
This problem introduces an inverse relationship constraint: instead of the *number* of coins being equal, the *total value* contributed by each denomination is equal.
If the value is constant, lower denominations require proportionally more coins to reach that same value.
### Step-by-Step Solution
* **Given:** Total coins = 175. Denominations = ₹ 1, 50p (₹ 0.50), 25p (₹ 0.25). The total monetary value contributed by each type is identical.
* **Calculation:** Let the total value contributed by each specific denomination be ₹ $V$.
* Because each of the 3 types contributes ₹ $V$, the total amount in the bag is $3V$. Our goal is to find $V$.
* Number of ₹ 1 coins needed to make ₹ $V$ = $\frac{V}{1} = V$
* Number of 50p coins needed to make ₹ $V$ = $\frac{V}{0.50} = 2V$
* Number of 25p coins needed to make ₹ $V$ = $\frac{V}{0.25} = 4V$
* The total number of coins is the sum of these quantities:
$$V + 2V + 4V = 175$$
$$7V = 175$$
$$V = 25$$
* Each denomination contributes ₹ 25 to the bag.
* Total amount in the bag = $3 \times V = 3 \times 25 = 75$.
### Exam Strategy & Shortcut
Since the value of each coin type is the same, the ratio of the *number of coins* is simply the inverse of their *face values*.
Face values ratio: 1 : 1/2 : 1/4.
Coin quantities ratio: 1 : 2 : 4.
Total ratio parts = $1 + 2 + 4 = 7$ parts.
7 parts = 175 coins $\implies$ 1 part = 25 coins.
Since the "1 part" corresponds to the ₹ 1 coins, there are 25 ₹ 1 coins, which are worth ₹ 25.
Since all 3 types have equal value, total amount = $25 \times 3 = 75$.
### Common Pitfall
Calculating $V = 25$ and immediately looking for 25 in the options. Remember that $V$ is the value of just *one* denomination type. You must multiply by 3 to get the total amount in the bag.
### Final Answer
**Therefore, the correct answer is ₹ 75.**