Answer:
115
Step-by-step explanation:
There is a common difference d between consecutive terms, that is
d = 7 - 1 = 13 - 7 = 19 - 13 = 25 - 19 = 6
This indicates the sequence is arithmetic with n th term
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Here a₁ = 1 and d = 6 , thus
a₂₀ = 1 + (19 × 6) = 1 + 114 = 115
Answer:
570
Step-by-step explanation:
100% represents the total number of students at the school
Divide 171 by 30 to find 1% then multiply by 100 for total
total number of students =
× 100 = 570
Answer:
-19.322
Step-by-step explanation:
− a + ( − b ) −a+(−b)
First step is to combine like terms
-a -a + -b + -b
-2a -2b
We know a = 6.05 and b = 3.611
-2 (6.05) -2(3.611)
-12.1 - 7.222
-19.322
Answer: <span><span>{x|x ∈ U and 2x is prime} is an empty set.
</span>Justification:
</span>
U = {x|x is a positive integer greater than 1} = {2, 3, 4, 5, 6, ...}<span>
1) {x|x ∈ U and (1/2) x is prime}
Take x = 4 => (1/2) 4 = 4 / 2 = 2 = prime, so this is not empty.
{x|x ∈ U and 2x is prime}
2) 2x = {4, 6, 8, 10, 12, } so none of them is prime, hence this is an empty set.
3) {x|x ∈ U and (1/2) x can be written as a fraction}
Take any x that is odd. For example x = 3
=> (1/2)x = (1/2)3 = 3/2 which is a fraction, so this is not an empty set.
2) {x|x ∈ U and 2x can be written as a fraction}
Take any value of x, for example x = 7 => 2 = 14, and 14 = 28 / 2 so this is not an empty set.
</span>