Question

From a cuboidal cardboard box of dimensions $80cm\times 40cm\times 15cm,6$ circles of radius $7cm$ were cut out from the front face. Find the surface area of the remaining box.

• A. $9176c{m}^2$
• B. $9066c{m}^2$
• C. $9776c{m}^2$
• D. $9076c{m}^2$

Answer 1

The correct option is D $9076c{m}^2$

TSA of cardboard box $=$ $2(lb+bh+hl)$

$=$ $2(80\times 40+40\times 15+15\times 80)$

$=$ $2(3200+600+1200)$

$=$ $10,000$ ${cm}^2$

Area of circle = $\pi r^2=\frac{22}{7}\times 7\times 7=154{cm}^2$

Surface area of remaining box $=$ $10000-(6\times 154)$

$=$ $10000-924$

$=$ $9076$ ${cm}^2$