At a restaurant the ratio of kids meals sold to adult meals was 5: 4. if there were 20 kids meal sold, what is the combined amount of kids and adult meals sold?

5:4 <--- the ratio
5x:4x  <--- what the ratio represents
5x:20 <--- 20 kids meals sold
20=4x <--- since the 4x was replaced by 20, this is true
x=5 <--- divide by 5
25:20 <--- plug x into the ratio
25 adult meals + 20 kids meals=45 total meals

The correct answer is c