Ruben has 6 new books for his collection. This increases his collection by 12%? How many books does he have now?

Ruben has 6 new books for his collection. This increases his collection by 12%

Let x be the number of books Ruben has before 6 new books added

x + 12% of x = x+6

x + 0.12x = x+6

1.12 x = x+6

Subtract x on both sides

0.12x = 6

Divide by 0.12

x = 50

6 new books are added for his collection

So 50 + 6 = 56

He have 56 books now.