567
google search
Google search results:
1: https://www.quora.com/A-310m-long-train-crosses-a-platform-in-one-minute-If-the-speed-of-the-train-is-54-km-hr-then-what-is-the-length-of-the-platform
++++++++++++++++
2: https://www.toppr.com/ask/en-af/question/a-310-m-long-train-crosses-a-platform-in-onenminute-if-the-speed-of-the/
++++++++++++++++
3: https://brainly.in/question/34594400
++++++++++++++++
4: https://www.lehman.edu/faculty/anchordoqui/SJ1.pdf
++++++++++++++++
5: https://www.exeter.edu/sites/default/files/documents/Math1_2019.pdf
++++++++++++++++
6: https://people.nscl.msu.edu/~zegers/testbank
++++++++++++++++
7: https://www.hoddereducation.co.uk/media/Documents/My%20Revision%20Notes/Pearson-Edexcel-A-level-Physics-Answers.pdf?ext=.pdf
++++++++++++++++
8: https://acp.copernicus.org/preprints/
++++++++++++++++
9: https://www.chegg.com/xml/qandamaster378.xml
++++++++++++++++
10: https://www.lapdonline.org/lapd_manual/volume_4.htm
++++++++++++++++