Answer:
1:u
Explanation:
Grey slabs = 1/5 of total slab
Say total slab = x
Then,
Grey slabs = 1x/5
We can represent
Yellow slabs = u/5
Then ratio of Grey to yellow would be;
Gray slabs / Yellow slabs = (1x/5)/(u/5)
=1/u
= 1:u
Since there are 55 slabs in total, then
Yellow slab would be = 55/5 = 11