### Home > CCAA > Chapter 8 Unit 7 > Lesson CC2: 8.1.2 > Problem8-27

8-27.

Mrs. Chen has two brothers. Mark is $7$ years older than Mrs. Chen and Eric is $11$ years younger than Mrs. Chen. The sum of all three of their ages is $149$. Use the 5-D Process to determine the age of Mrs. Chen.  Homework Help ✎

What are the equations you can write to relate the ages of Mrs. Chen, Mark, and Eric? How can you use these equations to find Mrs. Chen's age?

If $C=\text{Mrs. Chen′s age}$, $M=\text{Mark′s age}$, and $E=\text{Eric′s age}$ one of the equations is $C+M+E=149$.
Can you find the others?

Mrs. Chen is $51$ years old.