Tourists visited India from three different countries (Japan, Dubai, and Singapore) in three different years(2018, 2019, and 2020).

2018: In 2018, there were 1800 tourists who came to visit India. The number of tourists from Dubai in 2018 is \(33 {1\over 3}\)% of the total number of tourists from Singapore in 2019. The average number of tourists from Japan and Dubai in 2018 was 400.

2019: The number of tourists from Japan and Singapore in 2019 was 1,600. The ratio of the total number of tourists from Singapore in 2018 to that of tourists from Singapore in 2019 is 10:9. And the total number of tourists from Dubai in 2019 was equal to the total number of tourists from Dubai in 2020.

2020: The total number of tourists from Japan and Dubai together is equal to the total number of tourists from Singapore in 2020. Tourists who visited in 2020 were 1600. The total number of tourists from Japan in 2020 was twice that of tourists from Dubai in 2018.