Do you have more friends who can swim or friends who can't swim?
Can most of your friends swim?
英語だと日本語のように「どっちが多いですか」「どっちが少ないですか」と言う聞き方をすると不自然なので、次のように言うと良いでしょう。
ーDo you have more friends who can swim or friends who can't swim?
「泳げる友達の方が多い？それとも泳げない友達の方が多い？」
ーCan most of your friends swim?
「あなたの友達の多くは泳げますか？」
ご参考まで！
Do you have more friends who can swim or more friends who can't?
"友達で泳げる人と泳げない人どちらが多いですか"
- Do you have more friends who can swim or more friends who can't?
- Are there more people who can swim among your friends, or more who cannot?
- Among your friends, do you have more who can swim or more who can't?
どちらが少ないですか
- Do you have less friends who can swim or less friends who can't?
カナダ 
アメリカ合衆国 
