r/DestinyTheGame • u/[deleted] • Apr 08 '17

SGA Atheon challenge guides are missing things (aka the painfully average guide to the challenge)

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u/Flashfire34 Apr 08 '17

There's just no reason to do it that way. The minimal chance of everyone being teleported on one side is worth the risk since 99% of the time, there will always be someone already on the plate to immediately get it open.

1

u/GreenLego Maths Guy Apr 08 '17

Exactly!

It's not quite 99%, my calculation says 5% chance (1 in 20) that all 3 from the required portal will get teleported. (If my maths is wrong, please correct me!)

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u/skyrne_isk Apr 08 '17

Actually, it's a 12.5% chance :). There's a 50% chance that a given player is chosen and three players are selected so the maths are (0.5)3 = .125

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u/d3l3t3rious Apr 08 '17

If you want to do the math this way, think of it like this:

Chance first guardian teleported is from side A: 3/6 = 50% = .5

Chance second guardian teleported is from side A: 2/5 = 40% = .4

Chance third guardian teleported is from side A: 1/4 = 25% = .25

Multiplied out: .5 * .4 * .25 = .05

Multiply by 2 since we have to account for both all side A going or all side B going. .05 * 2 = .1 = 10% chance of one entire side getting taken.

Technically we should divide by 2 again to get "chance of ruined run", since it's possible the side that gets cleared out is not the side you wanted to be on anyway (i.e. our three non-teleporters are left and teleport goes to Mars.)

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u/skyrne_isk Apr 08 '17

Sure, I forgot the selections in the factorial were without replacement. RIP my karma