Mia has a rectangle of cloth. she dips the top5/8 of cloth in blue dye. she dips the bottom 9/20 of the cloth in yellow dye. the part of cloth dips in both turns green. wirk out fraction that turns green.

Converting the fractions into decimals will give you 0.625 and 0.45. Adding these decimals together will give you 1.075 telling you the dyes overlapped. Because the sum is over 100% the remainder, 0.075, would be the part that turns green.

0.075 as a fraction would be 3/40.
 
So I believe your answer is 3/40.

To see the total parts of the cloth, you need to have a common denominator.

5/8 * 5/5 = 25/40

9/20 * 2/2 = 18/40

The total cloth is 40/40. The top 25 parts were dyed blue, the bottom 18 parts were dyed yellow. 25+18 = 43

So 3/40 of the cloth is yellow+blue = green