Question

Mia is three years older than twice her sister Brooke's age.

The sum of their ages is less than $30$.

What is the greatest age Brooke could be

• A. $7$
• B. $8$
• C. $9$
• D. $10$

Answer 1

The correct option is C

$9$

Explanation for the correct option:

Finding the greatest age of Brooke :

Let the Brooke's age be $x$ $\text{yrs}$

Then, Mia's age $=2x+3\text{yrs}$

Given, Sum of Mia's age and Brooke's age is $30$.

$$\begin{gathered} \Rightarrow x+\left(2x+3\right)=30 \\ \Rightarrow 3x=27 \\ \Rightarrow x=9 \end{gathered}$$

Hence, the age of Brooke is $9\text{years}$.