Fernando has a prime number of books between 21 30. he says that if he takes 4 of the books away, he will be able to place the same number of books on each shelf of his bookcase. how many books does fernando have?

Fernando has 29 books

Step-by-step explanation:

The prime numbers between 21 and 30 are 23 and 29.

hence, the possible number of books Fernando has 23 or 29.

After taking 4 books away, the total number of books left can be :-

23-4=19

Since, 19 is not a square number so he cannot be able to place the same number of books on each shelf of his bookcase.

So Fernado doesn't have 23 books.

29-4=25

Also,

Here, 25 is a square number so he will be able to place the same number of books on each shelf of his bookcase.

Therefore,  Fernando has 29 books.

step-by-step explanation: