Answer: 2
Explanation:
Given : Harry needs 21 square meters of fabric for every 6 wizard cloaks he makes.
Using Unitary method , The number of cloaks can be made in 1 square meter fabric will be :-

Now , the number of cloaks made in 7 square meters of fabric will be :-

Hence, the number of cloaks made in 7 square meters of fabric =2