the external dimensions of an open box are 40 cm × 30 cm ×35 cm all of its walls are 2.5 cm thick. find the capacity of the box and the wood used in the box
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external dimensions =40cm×30cm×35cm
thickness of box =2.5cm
Now, for internal dimensions
length=40-5=35cm
width = 30-5=25cm
height=35-2.5=32.5cm
So
capacity of the box=35cm×25cm×32.5cm
=28,437.5 cm^3
Now
Total wood used in making the box = external capacity- internal capacity
=40×30×35 - 35×25×32.5
=42,000cm^3 - 28,437.5cm^3
=13,562.5cm^3
external dimensions =40cm×30cm×35cm
thickness of box =2.5cm
Now, for internal dimensions
length=40-5=35cm
width = 30-5=25cm
height=35-2.5=32.5cm
So
capacity of the box=35cm×25cm×32.5cm
=28,437.5 cm^3
Now
Total wood used in making the box = external capacity- internal capacity
=40×30×35 - 35×25×32.5
=42,000cm^3 - 28,437.5cm^3
=13,562.5cm^3
shweta92329870:
Pls tell me why have you subtracted 2.5 and not 5 in height ?
as box is open .so the above portion top of internal and external is same that's why i sub. height by 2.5 that is bottom portion
thnks for the help☺
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