Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: · Marks: · Difficulty:
The average age of three boys is 25 years and their ages are in the proportion 3 : 5 : 7. The age of the youngest boy is
(a)9 years
(b)15 years
(c)18 years
(d)21 years
Answer
Answer (as printed): B
Explanation
Sum of ages of 3 boys $=(25 \times 3)$ years $=75$ years. ∴ Age of the youngest boy $$=\left(75 \times \frac{3}{15}\right) \text { years }=15 \text { years. }$$
Explanation as extracted from the printed page; notation may be imperfect.