1. Invitations were sent to 17 relatives for a family get-together. Only 8 relatives came. How many relatives did not come?   2. Ronnie weighs 22 kg. His mother is 66 kg. How much more is his mother's weight (in kg)?   3. Mr. Gates will be 34 next year. His son is 25 years younger than him. How many years old is his son at present?   4. A family party has 30 adults, 16 boys, and 4 girls. How many more adults are there at the party than children?   5. Arthur is 15 years old. His aunt is 37. How many years older than him is his aunt?