Ages with time shift: Five years ago, the average age of A, B, C, and D was 45 years. Including P now, the present average age of all five is 49 years. Find the present age of P.

Introduction / Context:When an average is given for a past time, we can update totals by adding years for each person to obtain present totals.Given Data / Assumptions:

• Five years ago: average of A, B, C, D = 45 years
• Now: average of A, B, C, D, P = 49 years

Concept / Approach:Compute past total of four, add 5 years per person to get present total of the four, then find P from the five person total.Step-by-Step Solution:

Verification / Alternative check:Average check holds with computed values.Why Other Options Are Wrong:

• 64, 48, 40 years: Do not equal the difference between the five person present total and the updated four person present total.

Common Pitfalls:Forgetting to add 5 years for each of the four when moving from past to present totals.Final Answer: