1a) 40%
1a) -count the black squares-8 black squares
-count all the square making up the block-20 squares
-that gives us 8 out of 20 squares
-Then we multiply the whole thing by 5 out of five, so we get the denominator to be 100 [8×5 and 20×5]
-that is 40 out of 100, the same as 40%