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3 years ago

The sum of the first 1 million primes is N. Without knowing N's value, one can determine that the ones'digit of N cannot be

1 answer:

3 0

All primes are odd, except two. Therefore the sum of the first million primes is one even number plus 999999 odd numbers. Since odd*odd = odd, the first million primes must be even + odd = odd.

An odd number obviously has an odd final digit, so the only option that can be firmly rules out is b (which is even).

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One number is 7 more than another. The difference between their squares is 161. What are the numbers?

sergeinik [125]

X is 7 more than y
x>y then
difference betwen squares is 161 so

x=7+y
and
x²-y²=161

so
x=7+y
sub that for x in other equation

(7+y)²-y²=161
y²+14y+49-y²=161
14y+49=161
minus 49 both sides
14y=112
divide both sides by 14
y=8

sub back

x=7+y
x=7+8
x=15

the numbers are 15 and 8

3 0

3 years ago

Read 2 more answers

Find the midpoint of the segment with the given endpoints (5,-9) and (-2,-2)

QveST [7]

Another way to solve this is to use the Midpoint Formula. The midpoint of a segment joining points $(x_1,y_1)$ and $(x_2,y_2)$ is

$\left(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2} \right)$

So the midpoint of your segment is

$\left(\frac{5+(-2)}{2},\frac{-9+(-2)}{2}\right) = \left(\frac{3}{2},-\frac{11}{2} \right)$

Perhaps it helps to see that the x-coordinate of the midpoint is just the average of the x-coordinates of the points. Ditto for the y-coordinate of the midpoint; just average the y's.

6 0

3 years ago

in pennsylvania the percent of sales tax is 6%, what is the sales tax on a skateboard that costs $98?

Stells [14]

Answer:

$103.88

Step-by-step explanation:

$98 + 6% is 103.88.

6 0

2 years ago

The circumference of C is 72 cm. What is the length of (the minor arc)? A. 90 cm B. 10 cm C. 45 cm D. 8 cm E. 9 cm F. 7.2 cm

dangina [55]

Answer:

e. 9cm

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Let A = {1,2,3,..., 8, 9, 10} B = {4, 7, 10}

Dovator [93]

The answers to the questions are

(i) B - A = Ф / null set

(ii) A - B = {1, 2, 3, 5, 6, 8, 9}

(iii) (A - B) ∩ (B - A) = Ф / null set

(iv) (A - B) ∪ (B - A) = {1, 2, 3, 5, 6, 8, 9}

A set contains different elements which are mathematical objects of any kind such as numbers, points, spaces, lines e.t.c.

Different types of set are -singleton setsfinite and infinite setsempty or null sets equal sets unequal sets equivalent sets overlapping sets disjoint sets subsets super sets power sets universal sets

According to question,

i ] B - A = 0/null set

ii ] A - B = [ 1,2,3,5,6,8,9 ]

iii ] (A-B) n (B-A) = 0/ null set

iv ] (A-B) u ( B-A) = [ 1,2,3,5,6,8,9 ]

Hence, the answers to the questions are

(i) B - A = Ф / null set

(ii) A - B = {1, 2, 3, 5, 6, 8, 9}

(iii) (A - B) ∩ (B - A) = Ф / null set

(iv) (A - B) ∪ (B - A) = {1, 2, 3, 5, 6, 8, 9}

To understand more about Set Theory refer - brainly.com/question/13458417#SPJ9

4 0

1 year ago