Answer:
Luke shaded 20 squares on his hundredths grid.
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Bekka shaded 30 squares on her hundredths grid.
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Two decimals greater than Luke's decimal and less than Bekka's decimal.
=>

Between 0.20 and 0.30 the two decimals are 0.21 and 0.22 and so on.
Therefore, 0.21 and 0.22 are two decimals greater than Luke's decimal and less than Bekka's decimal.