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3 years ago

What is the sum of the digits of all 2-digit numbers from 10-99?

Mathematics

2 answers:

IRISSAK [1]3 years ago

7 0

Huh, well the sum is just adding the numbers together, so the answer is 4905.

Lesechka [4]3 years ago

3 0

This took forever to do but 176879

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A blind taste test will be conducted with 9 volunteers to determine whether people can taste a difference between bottled water

Aloiza [94]

Answer:

The answer is $\frac{1}{256}$

Step-by-step explanation:

If we assume that people cannot taste a difference between bottled water, then the probability of identifying tap water is 0.5

Thus, P(identify tap water)=0.5

The probability that at least 8 of the 9 people identify the tap water correctly is the sum of the probabilities

8 of 9 people identified correctly or
9 of 9 people identified correctly

Since P(identify tap water)=0.5 each probabilities are the same and equal to

$0.5^9$ = $\frac{1}{512}$

So we have $2*\frac{1}{512}$ = $\frac{1}{256}$

6 0

3 years ago

Length of the base of the given triangle is (x+3) units and the perpendicular height is (x-1)units. If the area of the triangle

Lana71 [14]

Step-by-step explanation:

the area of a triangle is

baseline × height / 2

so, in our case we know this is 10 :

(x+3)(x-1)/2 = 10

(x+3)(x-1) = 20

x² - x + 3x - 3 = 20

x² + 2x - 23 = 0

that is exactly the provided equation. so, yes, x satisfies it.

the general solution to a quadratic equation is

x = (-b ± sqrt(b² - 4ac))/(2a)

in our case

a = 1

b = 2

c = -23

x = (-2 ± sqrt(2² - 4×1×-23))/(2×1) =

= (-2 ± sqrt(4 + 92))/2 = (-2 ± sqrt(96))/2 =

= (-2 ± sqrt(16×6))/2 = (-2 ± 4×sqrt(6))/2 =

= -1 ± 2×sqrt(6)

x1 = -1 + 2×sqrt(6) = 3.898979486... ≈ 4

or using sqrt(6) ≈ 2.45

= -1 + 2×2.45 = -1 + 4.9 = 3.9 ≈ 4

x2 = -1 - 2×sqrt(6) = -5.898979486... ≈ -6

or using sqrt(6) ≈ 2.45

= -1 - 2×2.45 = -1 - 4.9 = -5.9 ≈ -6

x2 would give us negative lengths for the triangle, which does not make sense.

so, x = 4 is our solution.

and that makes the height x-1 = 4-1 = 3 units.

7 0

2 years ago

Rewrite the expression using the distributive property and the gcf 35+42

forsale [732]

Answer: 7(5+6)

Step-by-step explanation:

The greatest common factor is the largest number that can both be divisible by 35 and 42

The distributive property is where a number is distributed to both numerals in the equation

8 0

3 years ago

Read 2 more answers

Pls help ill mark brainliestttt

vichka [17]

Jfjdhdhfhdhdhfhfhffjfhfhfjfjfjfjfhfh

7 0

3 years ago

Read 2 more answers

Figure out how far these planets are from earth, and yes please do the first two questions too. It's science so no need to expla

Aleks [24]

mercury-73.667 million mi

venus-157.86 million mi

earth-24,860 miles (40,008 km) around

mars-133.1 million mi

jupiter-557.21 million mi

saturn-1.0058 billion mi

uranus-1.8797 billion mi

neptune-2.8704 billion mi

pluto-3.2505 billion mi

im sure this is accurate

4 0

3 years ago