[_-__---]

I get stuck after the first few subproblems on all three. Does anyone have a PDF of the solutions? Are the solutions ever released?

I'm a little rusty on my linear algebra.

[Smaug123]

I whipped up a quick answer to q2; I don't know if it's right.

https://www.patrickstevens.co.uk/misc/TokyoEntrance2016/Toky...

[ldjb]

Unfortunately, the page the PDF is linked from [0] does not provide solutions. I don't think they are available (officially, at least).

[0] http://www.i.u-tokyo.ac.jp/edu/entra/examarchive_e.shtml