Question

If the ratio of the ages of A and B is 3:5 and their sum is 40 years, what is the age of B?

• A. 15 years
• B. 20 years
• C. 25 years
• D. 30 years

Hint:

For ratio problems, express quantities as multiples of a variable (e.g., \( 3x, 5x \)), set up an equation based on the given sum, and solve for the variable.

Answer 1

The Correct Option is C

To solve the problem, we need to find the age of B given the ratio of ages and their sum.

1. Understanding the Concepts:

- Ratio: The ages of A and B are in the ratio 3:5.
- Sum of Ages: The total of their ages is 40 years.
- We use the ratio to express ages in terms of a common variable.

2. Given Values:

- Ratio of ages = 3:5
- Sum of ages = 40 years

3. Calculate Ages:

Let the common multiplier be \( x \).
Then, A's age = \( 3x \), B's age = \( 5x \).
Sum: \[ 3x + 5x = 40 \Rightarrow 8x = 40 \Rightarrow x = 5 \]

4. Find B's Age:

\[ 5x = 5 \times 5 = 25 \]

Final Answer:

The age of B is 25 years.