which of the following group of numbers are all prime numbers a.2,5,15,19 b.7,17,29,49 c.3,11,23,31 d.2,3,5,9,
antoniya [11.8K]
Prime numbers are those that cannot be divided by another number (other than themselves and 1). In other words, prime numbers have factors of themselves and 1.
For example, 3 is a prime number because its only factors are 3 and 1.
6 is not a prime number because it can be factored to 3*2.
Therefore, the correct answer is c. 3,11,23,31
Answer:
see explanation
Step-by-step explanation:
(a)
y =
- bx
substitute y = 6 , x = 1 into the equation
6 = a - b → (1)
substitute y = 0 , x = 2 into the equation
0 =
- 2b ( multiply through by 2 to clear the fraction )
0 = a - 4b → (2)
multiply (1) by - 4
- 24 = - 4a + 4b → (3)
add (2) and (3) term by term to eliminate b
- 24 = - 3a + 0
- 24 = - 3a ( divide both sides by - 3 )
8 = a
substitute a = 8 into (1) and solve for b
6 = 8 - b ( subtract 8 from both sides )
- 2 = - b ( multiply both sides by - 1 )
2 = b
Then a = 8 and b = 2
(b)
when x = 4
y =
- 2(2) = 2 - 4 = - 2
Answer:
Percent (%)' means 'out of one hundred':
p% = p 'out of one hundred',
p% is read p 'percent',
p% = p/100 = p ÷ 100.
91% = 91/100 = 91 ÷ 100 = 0.91.
100% = 100/100 = 100 ÷ 100 = 1.
Decrease number by 91% of its value.
Percentage decrease = 91% × 843
New value = 843 - Percentage decrease
Calculate the New Value
New value =
843 - Percentage decrease =
843 - (91% × 843) =
843 - 91% × 843 =
(1 - 91%) × 843 =
(100% - 91%) × 843 =
9% × 843 =
9 ÷ 100 × 843 =
9 × 843 ÷ 100 =
7,587 ÷ 100 =
75.87
Calculate absolute change (actual difference)
Absolute change (actual difference) =
New value - 843 =
75.87 - 843 =
- 767.13
Proof.
Calculate percentage decrease:
Percentage decrease =
91% × 843 =
91 ÷ 100 × 843 =
91 × 843 ÷ 100 =
76,713 ÷ 100 =
767.13
Step-by-step explanation:
Hope it is helpful....
Answer:
The correct answer is:
Stratified (c.)
Step-by-step explanation:
Stratified sampling technique is one in which the groups of data are divided into smaller groups or strata, based on shared common characteristics in these groups, and the samples randomly selected from each group in a proportional way. In this example, the sub-groups used is "times of the day" ie. morning, afternoon or evening. Other strata that can be used are; age, gender, continents etc. Stratification is done when the researcher wants to understand the relationships between the two or more groups. Stratified random sampling is also known as proportional random sampling or quota random sampling.