Future sum shift: The current sum of ages of a mother, daughter, and son is 87. What will their combined age be after 8 years?

Introduction / Context:
When every person in a group ages by the same amount, the total increases by (number of people) × (years). No individual ages are required.

Given Data / Assumptions:

• Present total = 87.
• Number of people = 3.
• Time shift = +8 years for each person.

Concept / Approach:
Total increase = 3 × 8 = 24; add to the current total.

Step-by-Step Solution:
1) Increment = 24.2) Future total = 87 + 24 = 111.

Verification / Alternative check:
This logic holds regardless of the individual ages as long as the group size remains three.

Why Other Options Are Wrong:
They use an incorrect increment (not 24) or arithmetic error.

Common Pitfalls:
Adding 8 only once rather than for each of the three people.

Final Answer:
111