Not necessarily true. I think for your purposes the answer would be true, however frequency is not the only factor! For instance, you could workout 10 times a week but it could be for 2 minutes with minima effort and you would easily be training at a higher level if you worked out 6 times a week for 60 min with high effort level. So frequency is not everything! Tell your instructor that and I bet he/she would have to change the wording of the question!