According to the text, questionnaires can address events and characteristics taking place when?

All of the above

1. In the past (Retrospective questions) – These ask about past experiences, behaviors, or events. 
2. In the present (Current time questions) – These focus on existing conditions, opinions, or actions. 
3. In the future (Prospective questions) – These inquire about future plans, intentions, or expectations. 

• A vessel contains 20 litres of acid. 4 litres of acid is taken out of the vessel and replaced by the same quantity of water. Next 4 litres of the mixture are with, drawn, and again the vessel is filled with the same quantity add left in the vessel with t
• The distance between two places, A and B, is 300 km. Two riders, on scooters start simultaneously from A and B towards each other. The distance between them after 2.5 hrs is 25 km. If the speed of one scooter of one scooter is 10 km/hr more than the other
• Study the following information carefully to answer these questions.A vehicle starts from point P and run 10 km towards North. It takes a right turn and runs 15 km. Now it runs 6 km after taking a left turn. Finally, it takes a left turn, runs 15 km and s
• In a committee there are 15 members. If two members whose ages are 45 years and 55 years are replaced by the two new members, then average age of 15 members is increased by 2 years. What is the average age (in years) of the new members?
• The bus fare and train fare of a place from Kolkata were Rs.20 and Rs.30 respectively. Train fare has been increased by 20% and the bus fare has been increased by 10%. The ratio of new train fare to new bus fare is