Please help with this! I will mark you as brainliest!

Answer:
[tex]\frac{1}{19}[/tex]
Step-by-step explanation:
Assume there is only 1 yellow cube, then
There are 3 times as many blue cubes, that is 3
and 5 times as many green cubes as blue, that is 5 × 3 = 15
Thus the total of cubes = 1 + 3 + 15 = 19 of which only 1 is yellow, thus
P(yellow ) = [tex]\frac{1}{19}[/tex]