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**mathxyz****Member**- From: Brooklyn, NY
- Registered: 2024-02-24
- Posts: 1,053

A coin is flipped 5 times. What is the probability of landing on heads 3 out of 5 times?

The probability of rain for the next 3 days is 60 percent. What is the probability of no rain for 2 out of 3 days?

A book has 300 pages. What is the probability of opening and closing the book 4 consecutive times and landing on any page between 100 and 250?

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**Keep_Relentless****Member**- From: Queensland, Australia
- Registered: 2024-05-05
- Posts: 61

I notice your questions have gotten trickier.

I'll make a start on the first one.

It's useful to consider the number of different ways you could have three heads.

You could have:

HHHTT

HHTHT

HHTTH

HTHHT

HTHTH

HTTHH

THHHT

THHTH

THTHH

TTHHH

That's 10 possibilities... out of how many in total?

K_R

"The most incomprehensible thing about the world is that it is comprehensible." -Albert Einstein.

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**mathxyz****Member**- From: Brooklyn, NY
- Registered: 2024-02-24
- Posts: 1,053

Keep_Relentless wrote:

I notice your questions have gotten trickier.

I'll make a start on the first one.

It's useful to consider the number of different ways you could have three heads.

You could have:HHHTT

HHTHT

HHTTHHTHHT

HTHTH

HTTHHTHHHT

THHTH

THTHHTTHHH

That's 10 possibilities... out of how many in total?

K_R

Not my questions at all. Questions come from different online sites.

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