Multiple choice

The average age of $A, B$ and $C$ is $25$ years. The Ratio of their ages is $3 : 5 : 7$. Find the age of $A$.

  1. $21\ years$
  2. $18\ years$
  3. $15\ years$

  4. Data Inadequate
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Sum of ages = 25 * 3 = 75. Ratio 3:5:7 means 3x + 5x + 7x = 75. 15x = 75, x = 5. Age of A = 3x = 3 * 5 = 15 years.

AI explanation

The total age of A, B and C is 25 multiplied by 3, which equals 75 years. Let their ages be 3x, 5x, and 7x based on the given ratio. The sum of these parts is 15x, so 15x equals 75, meaning x is 5. The age of A is 3x, which calculates to 15 years.

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