 Hi and welcome to the session. I am Neha and today I am going to help you with the following question. The question says there are two cuboidal boxes as shown in the adjoining figure. Which box requires the lesser amount of material to make? Before proceeding for the solution let's recall the formula of total surface area of cuboid and that is equal to 2 into l into b plus b into h plus h into l where l is the length of the cuboid b is the width of the cuboid and h is height. Also let's recall total surface area of a cube and that is equal to 6 into l square where l is the length of the site of the cube. This is the key idea for this question. Now let's see its solution. First we need to find the amount of material to make these two boxes so for that we will find the total surface area of both of these boxes. Let us consider box A first. Now as we can observe that the box A is a cuboid so we will write box A is a cuboid length equal to 60 centimeters width that is b is equal to 40 centimeters that is equal to 50 centimeters and height is represented by h. So let's find out its total surface area which is equal to 2 into l into b plus b into h plus h into l so let's write it here. Now we will substitute the values now l that is length is equal to 60 centimeters so 60 into b that is 40 plus b that is 40 into h height 50 plus height 50 into l that is length 60. Now here the unit will be centimeter into centimeter that is centimeter square so this will give us 2 into 2400 plus 2000 plus 3000 centimeter square that is 14800 centimeter square so the total surface area of the box A is 14800 centimeter square. Now let us consider box B here we can observe that box B is a cube with length equal to 50 centimeters so let's write box B is a cube with length that is l is equal to 50 centimeters so total surface area of the box B will be now we know that the total surface area of A cube is equal to 6 into l square so let's write it here 6 into l square now let's substitute the values into l square l is 50 centimeters so 50 square and the unit will be centimeter square so this will give us 6 into 2500 centimeters square that is equal to 15000 centimeters square now we want the total surface area of box A is 14800 centimeters square and the total surface area of the box B is 15000 centimeters square that means box A has lesser surface area so this implies box A requires lesser amount of material therefore box A is our required answer with this we finish this session hope you must have understood the question goodbye take care and have a nice day