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Figure This!


The three cubes will melt faster.



Complete Solution:

Suppose that each of the smaller cubes is 1 in. high. The area of one face of the cube is length times width: 1 x 1 = 1 or 1 sq. in.

On each cube there are six faces, each with an area of 1 sq. in. The total surface area for each of the cubes is 6 sq. in. The surface area of the three cubes is 3 x 6, or 18 sq. in.

The big block of ice has four faces, each with an area of 3 x 1 for a total of 12 sq. in. The block has two faces with the surface area of 1 x 1 for a total of 2 sq. in.

Thus, the surface area of the block of ice is 12 + 2 or 14 sq. in. The three cubes broken apart will melt more quickly since the surface area of 18 sq. in. is exposed while the block of ice has only 14 sq. in. exposed.

Think what happens when you cut the block into cubes. There is more exposed surface area so the cubes melt faster.

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