Find the total surface area of a cuboid with length 10 m, breadth 5 m, and height 3 m.

Introduction / Context:
The total surface area of a cuboid equals the sum of the areas of its six rectangular faces, compactly written as 2(lb + bh + hl). Substituting the three linear dimensions yields the answer in square units. This reinforces inserting correct pairs into the formula and avoiding arithmetic slips.

Given Data / Assumptions:

• l = 10 m, b = 5 m, h = 3 m.
• Surface area S = 2(lb + bh + hl).

Concept / Approach:
Compute each face pair area (lb, bh, hl), add them, and multiply by 2. Check units are in metres so the result is in square metres.

Step-by-Step Solution:
lb = 10 * 5 = 50bh = 5 * 3 = 15hl = 3 * 10 = 30Sum = 50 + 15 + 30 = 95S = 2 * 95 = 190 sq m

Verification / Alternative check:
Compute all six faces explicitly: two of each pair give 2*50 + 2*15 + 2*30 = 100 + 30 + 60 = 190, same result.

Why Other Options Are Wrong:
170 and 104–105 sq m arise from omitting a pair or misadding a term; only 190 satisfies the full formula.

Common Pitfalls:
Forgetting the factor 2; mixing dimensions; or computing perimeter-like sums instead of areas.

Final Answer:
190 sq m