Ask question

Ask question

All categories

3 years ago

12

Five divided by two multiplied by a number then decreased by eleven is equal to four. Find the number.

2 answers:

Ratling [72]3 years ago

7 0

Yea the first one is right

I am Lyosha [343]3 years ago

3 0

Answer:

the number = 8/5 or 1 3/5 or 1.6

Step-by-step explanation:

n = the number

5/2n - 11 = 4

5/2n - 11 + 11 = 5 / 2n

5/2n = 4

5/2n / 5/2 = n

4 / 5/2 = 8/5

You might be interested in

Y =x+4 what’s the answer?

topjm [15]

Step-by-step explanation:

The answer is five .just say x is one subst. into the equation i guess.

5 0

3 years ago

A Finance professor created a multiple-choice examination with 100 questions for his students. Each question has five possible

seropon [69]

Answer:

a. 0.011 or 1.1%

b. 31.56% or 0.3156

c. 99.94% or 0.9994

d. 3.42% or 0.0342

Step-by-step explanation:

Given

Number of multiple choice questions = 100

Probability of success for students who have attended lectures and done their homework = 0.85

a. Using binomial distribution

Probability of correctly answering 90 or more questions out of 100

$= \sum^{100}_{x=90}\left {100} \atop {x}} \right C (0.85)^x(0.15)^{100-x}\\=0.011$

Since,

In Binomial Distribution

$P(X=x) =\left {h} \atop {x}} \right.C P^x q^{n-x}$

where $x=0,1,...,n$

and $q=1-P$

Probability is therefore 1.1% or 0.011

b. Probability of correctly answering 77 to 83 questions out of 100

$= \sum^{83}_{x=77}\left {100} \atop {x}} \right C (0.85)^x(0.15)^{100-x}\\=0.3156$

The probability is therefore 31.56% or 0.3156

c. Probability of correctly answering more than 73 questions out of 100

$= \sum^{100}_{x=73}\left {100} \atop {73}} \right C (0.85)^x(0.15)^{100-x}\\=0.9994$

The probability is therefore 99.94% or 0.9994

d. Assuming that the student has answered randomly

Probability of success = 1/5 = 0.2

Probability of failure = 1 - 0.2 = 0.8

Probability of answering 28 or more questions correctly

$= \sum^{100}_{x=28}\left {100} \atop {x}} \right.c (0.2)^x(0.8)^{100-x}\\=0.0342$

The probability is therefore 3.42%

5 0

3 years ago

Sofian's current age is (2x + 3) times Mastura's age. Given that Mastura's current age is (x + 5) years and 6 years ago, the sum

Sliva [168]

${\large{\textsf{\textbf{\underline{\underline{Given :}}}}}}$

★ Sofian's current age is (2x + 3) times Mastura's age.

★ Mastura's current age is (x + 5) years

★ 6 years ago, the sum of their ages is 44 years.

${\large{\textsf{\textbf{\underline{\underline{To \: Find :}}}}}}$

★ The value of x.

${\large{\textsf{\textbf{\underline{\underline{Solution :}}}}}}$

<u>According to the question,</u>

Present age of Mastura = (x + 5) years

Present age of Sofian = (2x + 3) (x + 5) years, i.e :

$\longrightarrow \tt (2x + 3) (x + 5)$

$\longrightarrow \tt 2 {x}^{2} + 10x + 3x + 15$

$\longrightarrow \tt 2 {x}^{2} + 13x + 15 \: years$

Now,

Mastura's age 6 years ago = (x + 5) - 6

=> x + 5 - 6

=> x - 1

Sofian's age 6 years ago = 2x² + 13x + 15 - 6

= 2x² + 13x + 9

<u>Usin</u><u>g</u><u> </u><u>the</u><u> </u><u>condi</u><u>tion</u><u> </u><u>provided</u><u> </u><u>by</u><u> </u><u>the</u><u> </u><u>question</u><u>,</u><u> </u>

Mastura's age 6 years ago + Sofian's age 6 years ago = 44

$\longrightarrow \tt (x - 1) + (2 {x}^{2} + 13x + 9) = 44$

$\longrightarrow \tt x - 1 + 2 {x}^{2} + 13x + 9 = 44$

$\longrightarrow \tt 2 {x}^{2} + 14x + 8 = 44$

$\longrightarrow \tt 2 {x}^{2} + 14x + 8 - 44 = 0$

$\longrightarrow \tt 2 {x}^{2} + 14x - 36= 0$

• <u>Takin</u><u>g</u><u> </u><u>"</u><u>2</u><u>"</u><u> </u><u>commo</u><u>n</u><u>.</u>

$\longrightarrow \tt 2 ({x}^{2} + 7x - 18) = 0$

$\longrightarrow \tt {x}^{2} + 7x - 18 = \dfrac{0}{2}$

$\longrightarrow \tt {x}^{2} + 7x - 18= 0$

• <u>Usin</u><u>g</u><u> </u><u>splitting</u><u> </u><u>the </u><u>midd</u><u>le</u><u> </u><u>term</u>

$\longrightarrow \tt {x}^{2} + 9x - 2x - 18 = 0$

$\longrightarrow \tt x(x + 9) - 2(x + 9) = 0$

$\longrightarrow \tt (x + 9) (x - 2) = 0$

either $\tt (x + 9) = 0 \: \: or \: \: (x - 2) = 0$

$\longrightarrow \tt x = - 9 \: \: or \: \: x = 2$

[As the age cannot be negative. So x = - 9 is rejected]

$\therefore \tt \: x = \red{ 2}$

${\large{\textsf{\textbf{\underline{\underline{Verification :}}}}}}$

<u>According to the condition provided by the question, </u>

• Mastura's age 6 years ago + Sofian's age 6 years ago = 44

$\longrightarrow \tt x - 1 + 2 {x}^{2} + 13x + 9 = 44$

<u>Putti</u><u>ng</u><u> </u><u>x</u><u> </u><u>=</u><u> </u><u>2</u><u> </u><u>we</u><u> </u><u>get</u><u>,</u>

$\longrightarrow \tt 2 - 1 + 2( {2})^{2} + 13(2) + 9 = 44$

$\longrightarrow \tt 1 + 2 \times 4 + 26+ 9 = 44$

$\longrightarrow \tt 1 + 8 + 26+ 9 = 44$

$\longrightarrow \tt 9 + 26+ 9 = 44$

$\longrightarrow \tt 18 + 26 = 44$

$\longrightarrow \tt 44 = 44$

<u>Henc</u><u>e</u><u> verified</u><u>.</u>

$\begin{gathered} {\underline{\rule{290pt}{3pt}}} \end{gathered}$

Hope it helps you! :))

6 0

3 years ago

What number is 40% of 30? Will Upvote

diamong [38]

$\displaystyle x \ is \ 40\% of 30 \\ ------------- \\ x= \frac{40}{10\not0} \cdot 3\not0 \\ \\ x= \frac{40}{10} \cdot 3\\\\ \\x= \frac{120}{10} \\ \\ x=12$

3 0

3 years ago

Samantha paid for 26.25 for 3 books how much did it cost her

raketka [301]

Hope it helps, the question wasn't clear, so sorry if the answer is wrong

4 0

4 years ago