4. Lindiwe is twice as old as Preeya and six years older than Sue. Their combined ages total 39 years. How old is Lindiwe?

Let Lindiwe's age be \( L \), Preeya's age be \( P \), and Sue's age be \( S \). According to the problem, we have three pieces of information to set up our equations: 1. \( L = 2P \) (Lindiwe is twice as old as Preeya) 2. \( L = S + 6 \) (Lindiwe is six years older than Sue) 3. \( L + P + S = 39 \) (Their combined ages total 39 years) Now we can substitute \( P \) and \( S \) in terms of \( L \): From equation 1, \( P = \frac{L}{2} \). From equation 2, \( S = L - 6 \). Now plugging these into equation 3: \[ L + \frac{L}{2} + (L - 6) = 39 \] Combining the terms: \[ L + \frac{L}{2} + L - 6 = 39 \] This simplifies to: \[ \frac{5L}{2} - 6 = 39 \] Adding 6 to both sides: \[ \frac{5L}{2} = 45 \] Multiplying both sides by 2: \[ 5L = 90 \] Dividing by 5: \[ L = 18 \] So, Lindiwe is 18 years old!