1. Invitations were sent to 29 relatives for a family get-together. Only 21 relatives came. How many relatives did not come?   2. Michael weighs 18 kg. His mother is 60 kg. How much more is his mother's weight (in kg)?   3. Mr. Gates will be 39 next year. His son is 30 years younger than him. How many years old is his son at present?   4. A family party has 26 adults, 5 boys, and 2 girls. How many more adults are there at the party than children?   5. Arthur is 15 years old. His aunt is 42. How many years older than him is his aunt?