Answer:
3.0
Step-by-step explanation:
Here we have a rectangle split into ten parts with 7/10 shaded in blue. The question asks what decimal represents the portion, alright, let's go down the list.
0.003 is also known as 3 thousandths, meaning that we would need a thousand little squares as our figure. Clearly this isn't the case, so 0.003 is wrong.
0.03 is also known as 3 hundredths, meaning that we would need a hundred little squares as our figure, this also isn't the case, so 0.03 is wrong.
0.3 is known as 3 tenths, yes this could represent our figure, but it doesn't represent the finished portion, which would be 1.0, this means that only one part will be shaded in the figure we have now, leaving it to be wrong.
This leaves us with 3.0
