A set of n elements has 2n subsets. Our set has 4 subsets. Thus, we have the equation
2n =

That should be 2^n and not just 2n

If we have 4 subsets, then 2^n = 4 leads to n = 2 since 2^2 = 4.

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Here's an example.

A = {p,q}

The four subsets of set A = {p,q} are

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Here's an example with n = 3 elements. We'll have 2^n = 2^3 = 8 subsets now. Let's say we had B = {r,s,t}

Those 8 subsets of set B are...

Note that order does not matter within any given set. Something like {r,s} is the same as {s,r}.

2 over 5

step-by-step explanation:

the 2: 3 ratio is the length of the ac segment to the cb segment total length. this implies that the ratio between segment ac length and segment ab length is 2: 5. point c is 2/5 from a to b, so the required fraction is 2/5.

i got 10.28 but that rounds up to 10.3