Question

Two cubes each with 8 cm edge are joined end to end. The surface area of the resulting cuboid is:

• A. 1440 $c{m}^2$
• B. 830 $c{m}^2$
• C. 640 $c{m}^2$
• D. 560 $c{m}^2$

Answer 1

The correct option is C 640 $c{m}^2$

Two cubs with edge length 8 cm are joined

new length = 2 (8 cm) = 16 cm

new breadth = 8 cm

new height = 8 cm

Surface area of cuboid 2 (lb+bh+hl)

$=2[16\times 8+8.8+8\times 16]$

$2\left[320\right]=640c{m}^2$