A's age 4 years ago was four times the present age of 'B'. At present, C's age is thrice the age of 'B'. Also 'C' is 24 years younger than 'A'. What is the present age of 'C' ?
CBSE Assistant Secretary - 2024,
Answer: B
C is 60 years old.
Let B's present age be b. Then C = 3b, and since C is 24 years younger than A, A = 3b + 24. Four years ago A was \(3b + 20\), which equals four times B's present age:
\[ \begin{aligned} 3b + 20 &= 4b \\ b &= 20 \end{aligned} \]
So B is 20, C is \(3 \times 20 = 60\), and A is 84. Check: four years ago A was 80, which is four times 20.
The other options fail this check; for example C = 54 gives B = 18 and A = 78, and 74 is not four times 18.
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