Question

Assertion (A) : The surface area of the cuboid formed by joining two cubes of sides 4 cm each, end-to-end, is \( 160 \text{ cm}^2 \).
Reason (R) : The surface area of a cuboid of dimensions \( l \times b \times h \) is \( (lb + bh + hl) \).

Hint:

Watch out for partial formulas in the Reason section of Assertion-Reason questions.

Answer 1

Step 1: Understanding the Concept:
Total Surface Area of cuboid = \( 2(lb + bh + hl) \).
Step 2: Detailed Explanation:
Joined cubes dimensions: \( L = 8, B = 4, H = 4 \).
Area = \( 2(8 \times 4 + 4 \times 4 + 4 \times 8) = 2(32+16+32) = 160 \). (A is True).
Reason R states area is \( (lb + bh + hl) \). It lacks the factor of 2. (R is False).
Step 3: Final Answer:
Assertion is true, Reason is false.