4 2 6 1 3 8 9 5 8 1 6 5 1 5 8 5 3 9 4 9 2 3 2 1 5 7 2 6 2 4 2 7 4. If all the even digits are removed from the above arrangement, which of the following will be seventh from the right?

Explanation

Remove every even digit—2, 4, 6 and 8—from the given sequence. The remaining odd digits are 1, 3, 9, 5, 1, 5, 1, 5, 5, 3, 9, 9, 3, 1, 5, 7, 7. Counting from the right, the 7th digit is 9.