I’m confused on how to set 2 and 3 up. can you me?

2) if it refers to the gray shaded boxes out of all the boxes, then count them 5 rows × 5 columns = 5×5 = 25
The total is 10 rows × 10 columns = 10×10 = 100
Fraction: 25/100 ->> divide both by 25 = 1/4
Decimal: 0.25
Ratio: 25 grey boxes: (100-25) white boxes
= 25:75 ->> divide both by 25 = 1:3
Percent: means "out of 100" so we know it's 25 out of 100 = 25%

3) 27 is 75% of what??
let's make x = what we don't know

Now cross-multiply: multiply top left with bottom right and make equal to the bottom left times the top right
27×100 = 75x
75x = 2700
75x/75 = 2700/75
x = 36

21/2 or 5/2