5 items that are substitute or complements?

Question

does anybody know any objects or ideas that are substitutes or complements?

Answer 1

vcr's and video cassettes are compliments in consumption

typwriters and secretaries are compliments in production

coke and pepsi are substitutes in consumption

linux mainframes and windows mainframes are substitutes in production

Answer 2

coke and pepsi = substitute

McDonald's and KFC = substitute

Skirt and Pant = Substitute

Boxer and Brief = Substitute

Spectacle and Contact Lense = Substitute

Keyboard and Computer = Complement

Battery and Handphone = Complement

Pencil and Lead = Complement

Printer and Paper = Complement

Car and Fuel = Complement

Answer 3

I have some more easy examples.

1. Pen & Ink (Complementary Goods)

2. Bat & Ball (Complementary Goods)

3. Car & Petrol (Complementary Goods)

4. Rice & Wheat (Subsitute Goods)

5. Tea & Coffee (Subsitute Goods)