Frank is designing a new walkway for his house. He is using concrete stones to make the walkway. He knows he will need 50 pounds of sand for every 10 concrete stones he will lay in the walkway. Which equation describes the relationship between the amount of sand in pounds, s, and the number of concrete stones, c? A. s=10c+50
B. c=5s
C. c=10s+50
D. s=5c