If you would like to know how much will you have to pay for 1 pair of socks, you can calculate this using the following steps:
12 pairs of socks ... $5.79
1 pair of socks ... $x = ?
12 * x = 1 * 5.79 /12
x = 5.79 / 12
x = $0.4825
x = $0.48
Result: You will have to pay $0.48 per unit.