Rope costs $0.42 per foot. in a relation, the input is the number of feet of rope and the output is the cost.
is this relation a function? why or why not?

f(x) = 0.42x   ; x is the input as the length of rope in feet

                      ;  f(x) is the output as cost  

Step-by-step explanation:

For a relation to be a function there is a condition that in a function every input has a unique output. It means that for one input there should be only one output, two or more outputs are not allowed.

The function f(x)=0.42x satisfies the above condition to become a function.

(To find the function use the following method

Cost of total length of rope = (Cost of rope per foot) × (Length of rope in feet)

f(x) = 0.42 × x

f(x) = 0.42x

)

9 sandwiches per hour

step-by-step explanation:

when we have a rate, we want a 1 in the denominator

27/3 = 9

27 sandwiches/ 3 hours = 9 sandwiches/hour