Given that a function, f, has a domain of 1 ≤ x ≤ 5 and includes ordered pairs (1,4) and (5,15) select the ordered pair that could belong to function f.
a. (3,8)
b. (5,10)
c. (4,18)
d. (0,2)

Without multiplying, tell which product is larger and why. 5 × 1/3 or 5 × 2/3 a)5 × 1/3 because 1/3 is less than 2/3 b) 5 × 1/3 because 1/3 is greater than 2/3 c) 5 × 2/3 because 1/3 is less than 23 d) 5 × 23 because 1/3 is greater than 2/3