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3 years ago

You roll a fair 6 sided dice. What is p(not 5)?

Mathematics

1 answer:

liq [111]3 years ago

7 0

Answer:

p(not 5) = 5/6

Step-by-step explanation:

The probability that we roll a 5 is 1/6. So, the probability we don't roll a five is simple 1 minus that:

$1-\frac{1}{6} = \frac{5}{6}$

And that's your answer.

You might be interested in

What is the volume? 7 cm 5 cm 8 cm cubic centimeters

Flura [38]

Answer:

280 cm

or 280cm^2

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

Determine all prime numbers a, b and c for which the expression a ^ 2 + b ^ 2 + c ^ 2 - 1 is a perfect square .

kogti [31]

Answer:

The family of all prime numbers such that $a^{2} + b^{2} + c^{2} -1$ is a perfect square is represented by the following solution:

$a$ is an arbitrary prime number. (1)

$b = \sqrt{1 + 2\cdot a \cdot c}$ (2)

$c$ is another arbitrary prime number. (3)

Step-by-step explanation:

From Algebra we know that a second order polynomial is a perfect square if and only if $(x+y)^{2} = x^{2} + 2\cdot x\cdot y + y^{2}$ . From statement, we must fulfill the following identity:

$a^{2} + b^{2} + c^{2} - 1 = x^{2} + 2\cdot x\cdot y + y^{2}$

By Associative and Commutative properties, we can reorganize the expression as follows:

$a^{2} + (b^{2}-1) + c^{2} = x^{2} + 2\cdot x \cdot y + y^{2}$ (1)

Then, we have the following system of equations:

$x = a$ (2)

$(b^{2}-1) = 2\cdot x\cdot y$ (3)

$y = c$ (4)

By (2) and (4) in (3), we have the following expression:

$(b^{2} - 1) = 2\cdot a \cdot c$

$b^{2} = 1 + 2\cdot a \cdot c$

$b = \sqrt{1 + 2\cdot a\cdot c}$

From Number Theory, we remember that a number is prime if and only if is divisible both by 1 and by itself. Then, $a, b, c > 1$ . If $a$ , $b$ and $c$ are prime numbers, then $2\cdot a\cdot c$ must be an even composite number, which means that $a$ and $c$ can be either both odd numbers or a even number and a odd number. In the family of prime numbers, the only even number is 2.

In addition, $b$ must be a natural number, which means that:

$1 + 2\cdot a\cdot c \ge 4$

$2\cdot a \cdot c \ge 3$

$a\cdot c \ge \frac{3}{2}$

But the lowest possible product made by two prime numbers is $2^{2} = 4$ . Hence, $a\cdot c \ge 4$ .

The family of all prime numbers such that $a^{2} + b^{2} + c^{2} -1$ is a perfect square is represented by the following solution:

$a$ is an arbitrary prime number. (1)

$b = \sqrt{1 + 2\cdot a \cdot c}$ (2)

$c$ is another arbitrary prime number. (3)

Example: $a = 2$ , $c = 2$

$b = \sqrt{1 + 2\cdot (2)\cdot (2)}$

$b = 3$

4 0

3 years ago

Answer question 8,9 and 10 with full details.

Lelechka [254]

Answer:

See Explanation

Step-by-step explanation:

8. (1)

Area of trapezoid = 1/2(sum of || sides) *perpendicular distance

36 =1/2(x+ y) * 6

36 = ((x + y)*3

36/3 = x + y

12 = x + y

x + y = 12.... (1)

8(2)

It is given that:

x = 2y....(2)

From equations (1) & (2)

2y + y = 12

3y = 12

y = 12/3

y = 4

From equation (2)

x = 2y = 2*4

x = 8

Area of square = 1 square m

Side of square = 1 m

Area of circle = 1 square m

$\pi {r}^{2} = 1 \\ {r}^{2} = \frac{1}{\pi} \\ r = \frac{1}{ \sqrt{\pi} } \\ c = 2\pi \: r \\ c = 2\pi \times \frac{1}{ \sqrt{\pi} } \\ c = 2 \sqrt{\pi} \\ c = 2 \sqrt{3.14} \\ c = 2 \times 1.77200451 \\ c = 3.54400902 \\ c = 3.544 \\ difference = 3.544 - 1 = 2.544 \\difference \approx \: 2.54$