Ratio and proportion word problem

Question

It takes a train c hours to cover d miles. If the train travels k miles at the same rate, the number of hours it takes is

(1) cdk (4) 7y/12

(2) d/ck (5) 84y

(3) 12y/7

Answer 1

if it takes c hours to go d miles, let H = the number of hours needed to go k miles.

Then, the ratio is c hours/d miles = H hours/k miles

So, H = ck/d and that is not one of your answers? It is not clear what "y" represents?