Grecia has some Php 50 and Php 20 bills. The total amount of these bills is less than Php 2,500. Suppose there are 35 Php 50 bills. Which of the following is true about the number of Php 20 bills?
I. The number of Php 20-bills is less than the number of Php 50-bills.
II. The number of Php 20-bills could be more than the number of Php 50-bills.
III. The number of Php 20-bills is equal to the number of Php 50-bills.

a. I and II
b. I and III
c. II and III
d. I,II and III​