K is 5 years older than H. H is 3 years younger than R. R is 6 years older than C. C is 7 years younger than L. Based on this chain of age relations, who is the eldest among K, H, R, C and L?

Introduction / Context:
This is a logical age comparison question involving several people connected by a chain of older and younger relationships. Instead of requiring algebraic equations, it mainly tests your ability to interpret and combine relative age statements correctly. Such questions often appear in reasoning sections of aptitude tests to check clarity of thought and careful reading.

Given Data / Assumptions:

• K is 5 years older than H.
• H is 3 years younger than R.
• R is 6 years older than C.
• C is 7 years younger than L.
• We need to determine who is the eldest among K, H, R, C and L.

Concept / Approach:
The approach is to pick one person as a reference and express all other ages relative to that person using differences. It is convenient to choose C as the reference because several statements connect to C through R and L. Once the ages of R, H, K and L are written in terms of C, we can compare the expressions to see who has the largest value, and therefore who is the eldest. This process uses only basic arithmetic with plus and minus signs.

Step-by-Step Solution:
Step 1: Let the present age of C be c years. Step 2: R is 6 years older than C, so R age is c + 6. Step 3: H is 3 years younger than R, so H age is (c + 6) − 3 = c + 3. Step 4: K is 5 years older than H, so K age is (c + 3) + 5 = c + 8. Step 5: C is 7 years younger than L, so L age is c + 7. Step 6: Compare all expressions: C has c, H has c + 3, R has c + 6, L has c + 7, and K has c + 8. The largest among these is c + 8, so K is the eldest.

Verification / Alternative check:
To visualize, assign any convenient value to c, for example c = 10 years. Then R = 16, H = 13, K = 18 and L = 17. In this illustrative scenario, K is 18 years old, which is older than everyone else. Because only constant differences were used to relate ages to c, the relative ordering does not change if we choose a different value for c. Therefore, K is always the eldest regardless of the specific value of c, as long as all relations hold.

Why Other Options Are Wrong:
Option H: H age is c + 3, which is less than c + 8, so H cannot be the eldest.
Option R: R age is c + 6, still smaller than c + 8.
Option L: L age is c + 7, closer to K age but still one year younger than K.
Option C: C age is c, the smallest of all expressed ages, so C is definitely not the eldest.

Common Pitfalls:
A common mistake is to misread younger than and older than and reverse the sign when forming expressions. Another error is to try to assign actual numbers without maintaining the given differences properly, which can lead to an incorrect ordering. A reliable strategy is to choose a reference person, write everyone else age in terms of that reference, and then compare the resulting expressions directly. This ensures that relative age comparisons remain clear and consistent.

Final Answer:
The eldest among the five people is K.