Question

John always wears a shirt, pants, socks, and shoes. He owns 121212 pairs of socks, 333 pairs of shoes, 555 pairs of pants, and 555 shirts.

Answer 1

If you mean the quantity of ways to dress John, 
he can choose any one of his 12 pairs of socks to combine with any one of his 3 pairs of shoes and any one of his 5 pairs of pants and any one of his 5 shirts.
12 ways to choose pair of socks and 3 ways to choose pair of shoes and 5 ways to choose pant and also 5 ways to choose a shirt.
12*3*5*5=900.
900 ways to dress him...