C and E that is the answer
The <em>echo</em> number 20222022202220222022 is the <em>perfect</em> square of 4496890281.
<h3>What echo number is a perfect square</h3>
An <em>echo</em> number has a <em>perfect</em> square if its square root is also a <em>natural</em> number. After some iterations we found that <em>echo</em> number 20222022202220222022 is a <em>perfect</em> square:
The <em>echo</em> number 20222022202220222022 is the <em>perfect</em> square of 4496890281. 
To learn more on natural numbers, we kindly invite to check this verified question: brainly.com/question/17429689
Answer:
a. Isosceles + Acute
b. Scalene + Right
Step-by-step explanation:
a. The side markers show that 2 sides are equivalent in length, making it isosceles. The angles are all noticeably under 90 degrees, resulting in it being acute.
b. There are no side markers whatsoever, making it scalene. There is a right angle marker, resulting in the triangle being right.
To solve this problem, we make use of the Binomial
Probability equation which is mathematically expressed as:
P = [n! / r! (n – r)!] p^r * q^(n – r)
where,
n = the total number of gadgets = 4
r = number of samples = 1 and 2 (since not more than 2)
p = probability of success of getting a defective gadget
q = probability of failure = 1 – p
Calculating for p:
p = 5 / 15 = 0.33
So,
q = 1 – 0.33 = 0.67
Calculating for P when r = 1:
P (r = 1) = [4! / 1! 3!] 0.33^1 * 0.67^3
P (r = 1) = 0.3970
Calculating for P when r = 2:
P (r = 2) = [4! / 2! 2!] 0.33^2 * 0.67^2
P (r = 2) = 0.2933
Therefore the total probability of not getting more than
2 defective gadgets is:
P = 0.3970 + 0.2933
P = 0.6903
Hence there is a 0.6903 chance or 69.03% probability of
not getting more than 2 defective gadgets.
