An open box is made by cutting the congruent squares from the corners of a rectangular sheet of cardboard of dimension 20 cm × 15 cm. If the side of each square is 2 cm, the total outer surface area of the box is :
Options:
A . 148 cm2
B . 284 cm2
C . 316 cm2
D . 460 cm2
Answer: Option B Clearly, $$l$$ = (20 - 4) cm = 16 cm b = (15 - 4) cm = 11 cm and h = 2 cm ∴ Outer surface area of the box : $$\eqalign{ & = \left[ {2\left( {l + b} \right) \times h} \right] + lb \cr & = \left[ {\left\{ {2\left( {16 + 11} \right) \times 2} \right\} + 16 \times 11} \right] \cr & = \left( {108 + 176} \right) \cr & = 284{\text{ c}}{{\text{m}}^2} \cr} $$
Submit Comment/FeedBack