Problems on Ages — “Average age of A, B, C is 25 years; their ratio is 3 : 5 : 7. Find A’s present age.”
Verbal Reasoning
Problems on Ages
Difficulty: Easy
Choose an option
-
A12 years
-
B15 years
-
C18 years
-
D21 years
-
E24 years
Answer
Correct Answer: 15 years
Explanation
Introduction / Context:Average plus ratio is the standard “total and split” pattern. Recover the total from the average, then apportion by ratio parts to get each individual age.
Given Data / Assumptions:
- Average of three = 25 ⇒ total = 75.
- Ratio A : B : C = 3 : 5 : 7 (sum of parts = 15).
Concept / Approach:One part = total / number of parts. Then A = 3 parts, B = 5 parts, C = 7 parts.
Step-by-Step Solution:
Total age = 25 * 3 = 75.One part = 75 / 15 = 5.A = 3 * 5 = 15 years.Verification / Alternative check:Ages become (15, 25, 35). Average = (15 + 25 + 35)/3 = 75/3 = 25 ✓.
Why Other Options Are Wrong:12/18/21/24 are not equal to 3 parts with part size 5.
Common Pitfalls:Taking 25 directly as a part value or dividing by 3 incorrectly; always form the total first.
Final Answer:15 years