How much sheet (in cm²) will be needed to construct a cuboid of dimensions 10cm x 8cm x 6cm, if the lid is kept open?
Answer & explanation
Correct answer: option 3
Sheet required to build such cuboid = surface area of 4 lateral sides + area of bottom
= 2 h (l + b) + lb
= 2 × 6 (10 + 8) + (10 × 8)
= 216 + 80 = 296 cm²