Jonathan and his sister Jennifer have a combined age of 48. If Jonathan is twice as old as his sister, how old is Jennifer?

Question: Jonathan and his sister Jennifer have a combined age of 48. If Jonathan is twice as old as his sister, how old is Jennifer?

Let's use algebra to solve this problem.

Let J represent Jonathan's age, and let S represent Jennifer's age.

We are given two pieces of information:

Jonathan and Jennifer have a combined age of 48, which can be written as:

J + S = 48

Jonathan is twice as old as his sister, which can be written as:

J = 2S

Now, we can set up a system of equations with these two equations:

Equation 1: J + S = 48

Equation 2: J = 2S

We can substitute the value of J from Equation 2 into Equation 1:

2S + S = 48

Now, combine like terms:

3S = 48

To isolate S (Jennifer's age), divide both sides by 3:

S = 48 / 3

S = 16

So, Jennifer is 16 years old.