Write 0.9 as a fraction with a denominator of 10

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?

Rob filled 5 fewer plastic boxes with football cards than basketball cards. he filled 11 boxes with basketball cards.

In a rational number twice the numerator is 2 more than the denominator. if 3 is added to each, numerator and the denominator, the new fraction is 2/3. find the original number