Question

1.Find Perimeter and Area of rectangle whose length and breadth is 12 cm end 10 cm

2.There are 20 Boys and 15 Girls in a class. Find the Ratio a) Girls to Boys b) Boys to whole class



give in method and right answer otherwise reported​

Answer 1

$\large{ \underline{ \underline{ \red{\tt{Answer \: (1)}}}}}$

Given :

• Length of the rectangle = 12 cm
• Breadth of the rectangle = 10 cm

To Find :

• Area and perimeter of the rectangle.

Formulae used :

For calculating the area of rectangle, formula is given by,

$\boxed{ \bf{Area_{(Rectangle)} =l \times b}}$

For calculating the perimeter of rectangle, formula is given by,

$\boxed{ \bf{Perimeter_{(Rectangle)} = 2(l + b)}}$

Here,

• ${l}$ = length
• b = breadth

Calculations :

$\dag \: { \pink{ \sf{ \underline{ \underline{Calculating \: the \: area \: of \: rectangle :}}}}}$

Using formula,

$\star{\boxed{ \bf{Area_{(Rectangle)} =l \times b}}}$

Putting the values,

$\longrightarrow$ Area of rectangle = length × breadth

$\longrightarrow$ Area of rectangle = 12 × 10 cm

$\longrightarrow$ Area of rectangle = 120 cm²

• Hence, area of rectangle is 120 cm².

$\dag \: { \pink{ \sf{ \underline{ \underline{Calculating \: the \: perimeter \: of \: rectangle :}}}}}$

Using formula,

$\star{\boxed{ \bf{Perimeter_{(Rectangle)} = 2(l + b)}}}$

Putting the values,

$\longrightarrow$ Perimeter of rectangle = 2 (l + b)

$\longrightarrow$ Perimeter of rectangle = 2 (12 + 10)

$\longrightarrow$ Perimeter of rectangle = 2 × 22

$\longrightarrow$ Perimeter of rectangle = 44 cm

• Hence, the perimeter of rectangle is 44 cm.

____________________________________

$\large{ \underline{ \underline{ \red{\tt{Answer \: (2)}}}}}$

Given :

• Number of boys in class = 20 Boys
• Number of girls in class = 15 girls

To Find :

1. Ratio of girls to boys
2. Boys to whole class

Calculations :

$\underline{ \underline{ \bf{ \purple{1) \: Ratio \: of \: girls \: and \: boys \: - }}}}$

Given that,

• Number of girls = 15 girls

• Number of boys = 20 boys

Now, according to the question, let's find the ratio of girls to Boys.

→ Number of boys : Number of girls

Now, evaluating,

$\longrightarrow$ 20 : 15

$\longrightarrow$ 20/15

• Cancelling the numbers and converting in simplest form,

$\longrightarrow$ 4/3

• In ratio,

$\longrightarrow$ 4 : 3

Therefore, ratio of girls to Boys is 4 : 3.

$\underline{ \underline{ \bf{ \purple{2) \: Ratio \: of \: boys \: to \: whole \: class - }}}}$

• Total number of students = 35 students

→ 15 + 20

→ 35 students

And, number of boys is 20 Boys.

$\longrightarrow$ 20 : 35

$\longrightarrow$ 20/35

• Cancelling the numbers and converting in simplest form,

$\longrightarrow$ 4/7

• In ratio,

$\longrightarrow$ 4 : 7

Therefore, ratio of boys to whole class is 4 : 7.