Which number sentence is true ? `9 xx 1/9=1`

Write the following fractional number in descending order: 1/9,13/9,11/9,15/9,3/9

Express the following numbers in usual form : 1.0001 xx 10^9

Express the following numbers is usual form. 1.0001 xx 10^9

9 xx 9 xx 9 xx 9

The cubes of the digits 1,4,5,6 and 9 are the number ending in the same digits 1,4,5,6 and 9 respecitively (True/False).