Question

Shanti Sweets Stall was placing an order for making cardboard boxes for packing
their sweets. Two sizes of boxes were required. The bigger of dimensions
25 cm x 20 cm x 5 cm and the smaller of dimensions 15 cm x 12 cm x 5 cm. For all the
overlaps, 5% of the total surface area is required extra. If the cost of the cardboard is
4 for 1000 cm?, find the cost of cardboard required for supplying 250 boxes of each
kind.
thanks​

Answer 1

Answer:  Rs 7140

Step-by-step explanation:

Surface area of box = 2 (LB+BH+HL)

Surface area of box 1 , s1 = 2 ( 25 x 20 x 5 ) = 5000cm²  

5% of s1 = 5/100 * 5000 = 250 cm²        

Total surface area of s1 = 5000+ 250 = 5250cm³

Surface area of box 2 , s2 = 2 ( 15 x 12 x 5 ) = 1800cm²    

5% of s2 = 5/100 * 1800 = 90cm²

Total surface area of s2 = 1800+ 90 = 1890cm³

cost of cardboard per 1000cm = Rs 4

cost of 1 box of surface area s1 = (5250/1000) x 4

                                                    = Rs.21

cost 250 such boxes = 21 x 250 = Rs 5250

cost of 1 box of surface area s2 = (1890/1000) x 4

                                                    = Rs. 7.56

cost 250 such boxes = 21 x 250 = Rs 1890

Total cost = 5250+1890 = Rs. 7140