He will need 528 pieces of glass.
Hope this helps!
Please mark as brainliest because it helps me out a lot :)
If the ratio of green to blue food coloring is 1:2 and 6 drops of blue was used, meaning that you basically multiplied 2 by 3 in order to get 6. Then the number of green drops would be 3 (1*3=3). 6+3=9
The total amount of drops of food coloring is then 9.
Hope this helps! (: