Answer:
0.216
Step-by-step explanation:
If the probability of green, P(green) is 40%, the probability of red, P(red) is 60%.
The probability of a light being red is not affected by the colour of the previous light, so at each of the 3 lights, the probability of red is always 60%.
To find the probability that all three lights will be red, multiply the three probabilities together. (Convert them to decimals first).
0.6 x 0.6 x 0.6 = 0.216
Answer:
Step-by-step explanation:
Let the age be xy or 10x + y.
Reverse the two digits of my age, divide by three, add 20, and the result is my age, convert this to equation:
- (10y + x)/3 + 20 = 10x + y
- (10y + x)/3 = 10x + y - 20
- 10y + x = 3(10x + y - 20)
- 10y + x = 30x + 3y - 60
- 30x - x + 3y - 10y = 60
- 29x - 7y = 60
We should consider both x and y are between 1 and 9 since both the age and its reverse are 2-digit numbers.
Possible options for x are:
- 29x ≥ 7*1 + 60 = 67 ⇒ x > 2, at minimum value of y,
and
- 29x ≤ 7*9 + 60 = 123 ⇒ x < 5, at maximum value of y.
So x can be 3 or 4.
<h3>If x = 3</h3>
- 29*3 - 7y = 60
- 87 - 7y = 60
- 7y = 27
- y = 27/7, discarded as fraction.
<h3>If x = 4</h3>
- 29*4 - 7y = 60
- 116 - 7y = 60
- 7y = 56
- y = 8
So the age is 48.
Answer:
(e) csc x − cot x − ln(1 + cos x) + C
(c) 0
Step-by-step explanation:
(e) ∫ (1 + sin x) / (1 + cos x) dx
Split the integral.
∫ 1 / (1 + cos x) dx + ∫ sin x / (1 + cos x) dx
Multiply top and bottom of first integral by the conjugate, 1 − cos x.
∫ (1 − cos x) / (1 − cos²x) dx + ∫ sin x / (1 + cos x) dx
Pythagorean identity.
∫ (1 − cos x) / (sin²x) dx + ∫ sin x / (1 + cos x) dx
Divide.
∫ (csc²x − cot x csc x) dx + ∫ sin x / (1 + cos x) dx
Integrate.
csc x − cot x − ln(1 + cos x) + C
(c) ∫₋₇⁷ erf(x) dx
= ∫₋₇⁰ erf(x) dx + ∫₀⁷ erf(x) dx
The error function is odd (erf(-x) = -erf(x)), so:
= -∫₀⁷ erf(x) dx + ∫₀⁷ erf(x) dx
= 0
69 is the answer to all questions.
