Answer:
28
Step-by-step explanation:

each coind has a 1/2 probability of landing on heads
3 coins would be 1/2 x 1/2 x 1/2 = 1/8 probability
Answer:

General Formulas and Concepts:
<u>Pre-Alg</u>
- Order of Operations: BPEMDAS
- Equality Properties
Step-by-step explanation:
<u>Step 1: Define equation</u>
<u />
<u />
<u />
<u>Step 2: Solve for </u><em><u>x</u></em>
- Cross-multiply:

- Distribute 0.35:

- Multiply:

- Isolate <em>x</em> term:

- Isolate <em>x</em>:

- Rewrite:

<u>Step 3: Check</u>
<em>Plug in x to verify it's a solution.</em>
- Substitute:

- Multiply:

- Subtract:

- Evaluate:

I think the answer to that is A