If ƒ(x ) = 3x + 1 and and ƒ -1 = , then the ordered pair of ƒ(3) = (3, 10) (3, 2/3) (10, 3)

ƒ(x ) = 3x + 1

Switch x and y to find inverse

x = 3y + 1

3y = x - 1

y = 1/3 x - 1/3

ƒ -1 = 1/3 x - 1/3

ƒ(x ) = 3x + 1

ƒ(3) = 3(3) + 1 = 10

(3, 10)

answer: first option i.e. 'a' is correct.

step-by-step explanation:

since we have given that

number of minutes to wrap a small gift box = 4 minutes

we need to find the number of gifts to be wrapped in 5 minutes

since there is a direct variation, as the number of minutes will increase with   number of gifts to be wrapped.

so, let the number of gifts to be wrapped in 5 minutes be x.

so, it becomes,

hence, first option 'a'   is correct.