I'm pretty sure it's 22%
If it's not, then I'm sorry!!
Isn't it 1/8?
I hope this helped i think i just simplified xD
Total flour used = Sum of all the cups
Total = 2 cups + 0.5 cups + 1.75 cups
= 4.25 cups of flour
4.25 cups of flour was used.
Hope this explains it.
Let Issac work for x hours, and Ruby works 8 hours more than of Issac, so Ruby work for
hours.
And Svetlana worked four times of Ruby, therefore Svetlana worked for

And total hours they worked together is 136. That is

So Issac worked for 16 hours, Ruby worked for 24 hours and Svetlana worked for 24 times 4 equals 96 hours .
6 divided by some number.