- #1
estex198
- 14
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While I know the answer to this problem, I can't figure out *how* to get it.
With the 5x5 array there are 25 total blocks and 15 colored blocks. I thought maybe I could use ratios and cross multiply: 15/25 = x/441, but this isn't giving me 79. I know 79 is the correct answer not only because its shown in the back of the book, but because I actually took a ruler and completed the pattern on paper (tedious as it was, I was really frustrated and needed to know I wasnt wasting my time.) Please help!
Carmelo has been commissioned to create a decorative wall for the 21st Annual X Games consisting of a square array of square tiles in a pattern forming a large X. The following example shows a pattern with 5 rows and 5 columns. If the wall will have a similar pattern with 21 rows and 21 columns, how many of the colored tiles will be needed?
View attachment 4368
View attachment 4368
With the 5x5 array there are 25 total blocks and 15 colored blocks. I thought maybe I could use ratios and cross multiply: 15/25 = x/441, but this isn't giving me 79. I know 79 is the correct answer not only because its shown in the back of the book, but because I actually took a ruler and completed the pattern on paper (tedious as it was, I was really frustrated and needed to know I wasnt wasting my time.) Please help!