The decimals that are less than 0.47 are 0.38 and 0.5.
To solve this problem
We can compare each of the above possibilities (0.38, 0.64, 0.5, 0.9) with 0.47 to determine which decimal is smaller than 0.47.
0.38 < 0.47
0.64 > 0.47
0.5 < 0.47
0.9 > 0.47
Therefore, the decimals that are less than 0.47 are 0.38 and 0.5.