Here, you do the same as the previous one, keeping in mind that X cuts TW in a 2:1 ratio.

15.80 * 1.05 should give you the answer
A method to solve it would be would be:
First converting 5% to a decimal then multiplying that by 15.80 in order the find 5 percent of 15.80...Afterwards you have to add that value to the original 15.80 ..And you should end up with the same answer.
Do you mean 1/2 of 1/4 if so it’s just timsing the numerator by the numerator and the denominator by the denominator. So, 1 x 1 = 1 and 2 x 4 = 8
Therefore it’s 1/8!
If you didn’t understand I’ll gladly elaborate!