If 1 is added to each odd digit and 2 is subtracted from each even digit in the number 32167854, how many digits will appear twice in the new number thus formed?

Given: 32167854

Add 1 to each odd digit

Subtract 2 from each even digit

Now go through each digit:

3 is odd → 3 + 1 = 4

2 is even → 2 - 2 = 0

1 is odd → 1 + 1 = 2

6 is even → 6 - 2 = 4

7 is odd → 7 + 1 = 8

8 is even → 8 - 2 = 6

5 is odd → 5 + 1 = 6

4 is even → 4 - 2 = 2

So, the new number is:
4, 0, 2, 4, 8, 6, 6, 2

So, three digits appear twice. 2, 4, 6

Three digits will appear twice in the new number thus formed.

Thus, correct option is (c).