1.There are two cuboidal boxes as shown in the adjoining figure. Which box requires the lesser amount of material to make?

We have, the total surface area of first box=\( 2(lb + bh + lh)\)
\(= 2 (60 \times 40 + 40 \times 50 + 60 \times 50) cm^2\)

\(= 200 (24+20+30) cm^2\)

\(= 200 \times 74 cm^2=14800 cm^2\)

Also, the total surface area of second box= \(6 (Edge)^2\)

\( = 6 \times 50 \times 50 cm^2= 15000 cm^2\)

So, the first box i.e., (a) requires the least amount of material to make because the total surface area of first box is less than that of the second.