All categories

2 years ago

The value of x in this system of equations is 1.

Mathematics

2 answers:

Ber [7]2 years ago

6 0

The value of y is 6 :)

denis-greek [22]2 years ago

6 0

Answer:

Step-by-step explanation:

You might be interested in

45+ 46+47+ 48+ ... 113 + 114Gauss approach

Doss [256]

Answer:

$5565$

Step-by-step explanation:

$1+2+3+4...+113+114=\frac{114*115}{2} =6555$

$1+2+3+4 ... +43+44=\frac{44*45}{2} =990$

Thus, $45+46+47+48...+113+114=$ $6555-990=5565$

3 0

3 years ago

How can you find the probability of a simple event if the total number of equally likely outcomes is 20?

dimaraw [331]

You can divide the total number of outcomes.

5 0

2 years ago

There is a 10% sales tax on a purchase of $13.50 how much is the tax

raketka [301]

Answer:

1.35

Step-by-step explanation:

13.5/100 times 10 = 1.35

8 0

3 years ago

Read 2 more answers

The guttering hold up to 20 litre of rain water. Work out the length of guttering in meters if the diameter is 11.5cm.

bazaltina [42]

Answer:

1107.0213 cm

Step-by-step explanation:

Assuming this gutter is half a cylinder,

Volume of half a cylinder = 0.5(πr²l)²

where, Volume = 20l, π = 3.142, r = 0.5(11.5) and l = ?

But, the other units are in cm while the Volume is in liters, so let's convert the liters to cm³

It would be easier to convert the liters to m³ then to cm³ rather than converting directly. So,

1000 L = 1 m³

1 L = ?

1 ÷ 1000 = 0.001 m³

1 m³ = 1,000,000cm³

0.001 m³ = ?

0.001 x 1,000,000 = 1000 cm³

So, if 1 L = 1000 cm³

20 L = ?

20 x 1000 = 20,000 cm³

Thus, 20,000 = 0.5(3.142 x 0.5(11.5) x l)

20,000 = 0.5(3.142 x 5.75 x l)

20,000 = 18.0665l

Make l the subject and divide both sides by 18.0665

length = 1107.0213 cm

6 0

2 years ago

In a MBS first year class, there are three sections each including 20 students. In the first section, there are 10 boys and 10 g

KIM [24]

Answer:

$3.52 \times 10^{-9} = 3.52 \times 10^{-7}\%$ probability that all the 15 students selected are girls

Step-by-step explanation:

The selection is from a sample without replacement, so we use the hypergeometric distribution to solve this question.

Hypergeometric distribution:

The probability of x sucesses is given by the following formula:

$P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}$

In which:

x is the number of sucesses.

N is the size of the population.

n is the size of the sample.

k is the total number of desired outcomes.

Combinations formula:

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

All girls from the first group:

20 students, so $N = 20$

10 girls, so $k = 10$

5 students will be selected, so $n = 5$

We want all of them to be girls, so we find P(X = 5).

$P_1 = P(X = 5) = h(5,20,5,10) = \frac{C_{10,5}*C_{10,5}}{C_{20,5}} = 0.0163$

All girls from the second group:

20 students, so $N = 20$

5 girls, so $k = 5$

5 students will be selected, so $n = 5$

We want all of them to be girls, so we find P(X = 5).

$P_2 = P(X = 5) = h(5,20,5,5) = \frac{C_{5,5}*C_{15,5}}{C_{20,5}} = 0.00006$

All girls from the third group:

20 students, so $N = 20$

8 girls, so $k = 8$

5 students will be selected, so $n = 5$

We want all of them to be girls, so we find P(X = 5).

$P_3 = P(X = 5) = h(5,20,5,8) = \frac{C_{8,5}*C_{12,5}}{C_{20,5}} = 0.0036$

All 15 students are girls:

Groups are independent, so we multiply the probabilities:

$P = P_1*P_2*P_3 = 0.0163*0.00006*0.0036 = 3.52 \times 10^{-9}$

$3.52 \times 10^{-9} = 3.52 \times 10^{-7}\%$ probability that all the 15 students selected are girls

7 0

2 years ago