Sara is twice as her youngest brother.if the difference between the ages is 15years.how old is her youngest brother

1 answer

Let's denote the age of Sara as \( S \) and the age of her youngest brother as \( B \).

According to the information given:

  1. Sara is twice as old as her youngest brother: \[ S = 2B \]

  2. The difference between their ages is 15 years: \[ S - B = 15 \]

Now we can use these two equations to solve for \( B \).

Substituting the first equation into the second equation:

\[ 2B - B = 15 \]

This simplifies to:

\[ B = 15 \]

Now that we have the age of the youngest brother, we can find Sara's age:

\[ S = 2B = 2 \times 15 = 30 \]

So, Sara is 30 years old, and her youngest brother is \( \textbf{15 years old} \).