Question

A sequence of patterns is made from circular tiles and square tiles. Here are the first three patterns in the sequence:

Answer 1

Answer:

  a) 49

  b) 84

  c) (B) -- always odd

Step-by-step explanation:

We observe that the number of square tiles is the square of the pattern number. The number of circular tiles is 1 more than the pattern number on each side of the square.

  square tiles = n²

  circular tiles = 4(n +1)

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a)

7² = 49 square tiles are needed for pattern number 7.

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b)

4(20+1) = 84 circular tiles are needed for pattern number 20.

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c)

The parity of the number of square tiles matches the parity of the pattern number. (The square of a number has the same parity as the number.) Since 4 is a factor in the number of circular tiles, its parity is always even. The parity of the total number of tiles will match the parity of the pattern number.

When the pattern number is odd, the total number of tiles will always be odd. (B)