This is false. If we assumed the prime numbers were closed under subtraction, then the difference of any two primes would also get us a prime number.
Take the prime numbers 11 and 7. Their difference, 11 - 7, is 4, but 4 is composite, as it has 2 as a factor other than 1 and 4. All we need is this one counterexample to prove that prime numbers are <em>not </em>closed under subtraction.
Answer:
8
Step-by-step explanation:
Step-by-step explanation:
3x -1 +2x + 4 x +1 = 180
9x = 180
X= 20
<ABC = 59
< CB D = 40
< DBE = 81
Answer:
(a) 0.0833 or 8.33%
(b) 0.40 or 40%
Step-by-step explanation:
Parts line one (n1) = 1,000 parts
Defects line one (d1) = 100 parts
Parts line two (n2) = 2,000 parts
Defects line two (d2) = 150 parts
Total number of parts (n) = 3,000 parts
a. Probability of a randomly selected part being defective:
The probability is 0.0833 or 8.33%
b. Probability of a part being produced by line one, given that it is defective:
The probability is 0.40 or 40%.