In: Economics
1) beef and lamb are substitutes to each other and it the first pair here. They are substitutes because people consume them alternative to each other where if the price of beef increases, then people will prefer to eat more lamb as a result of which the demand for lamb increases and vice versa. Therefore they are substitutes
2) Cigars and Chewing gum are complements because chewing gums are used to offset the smell created by cogs and if the price of cigars increase, people consume less cigars with which demand for chewing gums also reduce as a result of which demand curve of chewing gums shift left.
3) Radio and television are substitutes to each other because people can either listen to a radio or watch a television where if the price of radio increased, people would then prefer to watch television with which demand for television increases and the demand curve for television shifts right.