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.

]]>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 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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