Question

a log of wood of dimensions 2m ×20cm ×10cm is cut into small blocks of 10cm ×5cm ×4cm.How many blocks will we get?What wil be the total surface area of all these blocks?

Answer 1

answer is 2m=200cm, so it's really 
200cm×20cm×10cm is cut on small blocks of 10cm×5cm×4cm 
The first block has a volume of 40,000 cubic cm.
The second block has a volume of 200 cubic cm. 
The first block contains volume equal to 200 of the second. 
The second sized blocks have 6 faces 2*((10*5)+10*4)+(4*5)) = 210 sq cm (you see, a rectangular solid has 2 of each of the 3 sized faces, so 3 multiplies, then times 2) 
210 sq cm each times 200 blocks is 42,000 sq cm. 
(thank you for reading my note and reposting)

Answer 2

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