Pamela: ¿Cuánto cuesta la computadora? In English this means: Pamela, how much does the computer cost? "Cuánto" is used as how much. When it's used as a question it goes with accent mark. "Quién" means who, "Por qué" means why and "cómo" means how. Cuánto is the only possible option to complete the question. All the options have accent mark because they are supposed to go on a question. When they are used in a regular sentence, they don't have the accent mark.
