adeth has some Php10 and Php5 coins. The total amount of these is at most Php750. Suppose there are 50 Php5-coins. Which of the following is true about the number of Php10-coins

I. the number of Php10-coins is less than the number of Php5-coins
II. The number of Php10-coins is more than the number of Php5-coins
III. the number of Php10-coins is equal to the number of Php5-coins
A. I and II B. I and III C. II and III D. I, II, and III

10x + 5y < 750
10x + 5(50) < 750
10x + 250 < 750

10x < 500
10 10
x<50