1. which relation represents a function?

a] x = 1, 1, 1, 1, 1
y = 2, 3, 4, 5, 6

b] x = 1, 2, 3, 4, 5
y = 5, 4, 3, 2, 1

c] x = 1, 2, 1, 2, 1
y = 0, 1, 2, 3, 4

d] x = -2, -1, 0, -1, -2
y = 2, 3, 4, 5, 6

2. the function f(x) varies directly with x and f(x) = 2 where x= 10

what is the value of f(x) if x= 40

a] 320
b] 45
c] 200
d] 8