Answer:
The fraction of tiles that will be the color of "sand" is 23/60
Explanation:
we know that
The sum of the fractions of the tiles must be equal to 1
Let
x ----> the fraction of tiles that will be the color of "sand"
we have that

solve for x
Find the Least Common Multiple of denominators

Multiply both sides by 60

simplify


therefore
The fraction of tiles that will be the color of "sand" is 23/60