On Maisha’s birthday, 13 friends and 5 relatives came to her house. What is the total number of guests came to her house on her birthday?

During storm, mangoes fell from tree in Apu's house. Apu collected 6 mangoes and his sister collected 11 mangoes. How many mangoes did they collect altogether?

Rafiq had 10 colours pencils for drawing the pictures. He bought 9 more pencils from the shop. How many coloured pencil does he has?