Question

Shelf a has 4/5 of the number of books that shelf b has . If 25% of the books in a are transferred to b and than 25% of the books from b are transferred to a then the percentage of the total number of books that a will have is

Answer 1

Both Shelves have same number of books after transfers

1) Let the number of books in shelf B be x.

Then, number of books in shelf A would be 4x/5 .

2) First transfer : 25% of books of A to B

Books in A = 4x/5

Transferred books = (25/100) *4x/5 =  x/5

Remaining books in A = 4x/5 - x/5 = 3x/5

Books in B = x+x/5 = 6x/5

3) Second Transfer : 25% of books of B to A

Books in B = 6x/5

Transferred books = (25/100) * 6x/5 = 3x/10

Remaining books in B = 6x/5 - 3x/10 = 9x/10

Books in A = 3x/5 + 3x/10 = 9x/10

4) Hence, both shelves now have same number of books