Google MAPs knows, you can calc and compare like this.
https://goo.gl/maps/V5ZHHYPidqS2In Japan, the subway is not called "Metro", and in Tokyo, subway companies are only
"Toei(means Bureau of Transportation. Tokyo Metropolitan Government.)" and
"(Tokyo) Metro", called only "Metro" usual as nick, let's memorize it bc it is often misunderstood.
https://www.kotsu.metro.tokyo.jp/eng/http://www.tokyometro.jp/lang_en/index.htmlBut only the subway is not a way of traveling in Tokyo.
https://en.wikipedia.org/wiki/Transport_in_Greater_TokyoIt is not necessary to memorize all the route map of railways,
but it is safer to know the positional relationship of the major/main stations.
https://www.flickr.com/photos/kzaral/3373021846/PASMO can be used by most transportation in Tokyo and major big cities in Japan
and convenience stores and more as e-money, but even if buy both you will not lose.
PASMO is very convenient as without extra cashes(coin,bills), but it will not be a big discount.
https://www.pasmo.co.jp/en/use/And, that subway pass is not 3 days, "72 hrs" is.
https://www.tokyometro.jp/en/ticket/value/travel/index.htmlIf the start of use of the first day is late, you can use the fourth day.
Personally, I think that it will remain in my memory even if I move while looking at the scenery.
The Japanese subway is safest in the world, but it is not worth more than that.
(Although it seems interesting if you are a one of big railway/train fan.)
The traffic network in mid Tokyo is more complicated than you can imagine,
but the actual distance traveled is not so long also the fare is not high.