Half of the children in a library group like pets, one fourth don't like pets and seven children do not have any

Mathematics

1 answer:

erik [133]2 years ago

3 0

Answer:

14 children

Step-by-step explanation:

Half the children like pets and a quarter of the children do not, so another quarter does not have preference. Let x = total number of children, and we would have this equation.

0.25x = 7

x = 28

Since we are asked to give the number of children who like pets, 28/2 = 14 is the answer.

You might be interested in

the sides of a rectangle are the ratio 2:5. (for every 2cm of the width, the length is 5cm) the perimeter of the rectangle is 70

viva [34]

------------------------------------------------------------------------------------
Ratio
------------------------------------------------------------------------------------
Width : Length
2 : 5

Let x be the scale factor

Width : Length
2x : 5x

------------------------------------------------------------------------------------
Form equation and solve x
------------------------------------------------------------------------------------
Perimeter = 2(Length + Width)
70 = 2(5x + 2x)
70 = 2(7x)
70 = 14x
14x = 70
x = 5

------------------------------------------------------------------------------------
Find Length and Width
------------------------------------------------------------------------------------
Length = 5x
Length = 5(5)
Length = 25

Width = 2x
Width = 2(5)
Width = 10

------------------------------------------------------------------------------------
Answer: Length = 25 cm, Width = 10 cm
------------------------------------------------------------------------------------

4 0

3 years ago

Evaluate the determinant for the following matrix: 1 4 4 5 2 2 1 5 5

Elina [12.6K]

A Laplace expansion along the first row gives

$\begin{vmatrix}1&4&4\\5&2&1\\1&5&5\end{vmatrix}=1\begin{vmatrix}2&1\\5&5\end{vmatrix}-4\begin{vmatrix}5&1\\1&5\end{vmatrix}+4\begin{vmatrix}5&2\\1&5\end{vmatrix}$
$=1(10-5)-4(25-1)+4(25-2)$
$=1$