Answer:
30
Step-by-step explanation:
90+2x+x=180
3x=90
x=30
Sample space: H1, H2, H3, H4, T1, T2, T3, T4
All outcomes if the card is three: H3, T3
I was unclear about the last two parts of the question.
1. Change x = 4t into x = 3t

so

Answer A and D are wrong.
2. Change x = 4t into x = 2t

and

Answer b is correct.
3. Change x = 4t into x = 8t

and

Answer C. is correct, E. is wrong.
Answer:
4.F(x) > 0 over the intervals (-0.7, 0.76) and (0.76, ∞).
Step-by-step explanation: