Question

I have 2 questions
STEP BY STEP ANSWERS NEEDED
1) Find the area of rectangle, whose perimeter is 240m & length is 40m.
2)) Find the whole quantity if 7% of it is 490

Answer 1

$\underline{\it\ Question \ 1}$

Given :-

• Perimeter of rectangle= 240cm
• Length of rectangle 40cm

To Find :-

We have to find the Area of rectangle

Solution:-

Let the breadth of rectangle be x

Now first find the breadth then the area

$\underline{\blue{\sf\ Perimeter\ of\ Rectangle= 2(l+b)}}\\ \\ \\ :\implies\sf\ 240= 2(40+x)\\ \\ \\ :\implies\sf\ \cancel{\dfrac{240}{2}}= 40+x\\ \\ \\ :\implies\sf\ 120=40+x\\ \\ \\ :\implies\sf\ 120-40=x\\ \\ \\ :\implies\sf\ 80=x\\ \\ \\ \therefore{\purple{\sf\ Breadth=80cm}}$

Now Area of rectangle

$\underline{\boxed{\sf\ Area\ of\ Rectangle= \ell \times b}}\\ \\ \\ :\implies\sf\ Area= 80\times 40\\ \\ \\ :\implies\sf\ Area= 3200cm^2$

$\underline{\textsf{\textbf{\ Area\ of\ Rectangle= 3200cm}}^2}$

$\underline{\it\ Question \ 2}$

Let the total quantity be a

Now 7% of a =490

• We have to find the value of a

Solution :-

$:\implies\sf\ 7\%\ of\ a= 490\\ \\ \\ :\implies\sf\ \dfrac{7}{100}\times \ a= 490\\ \\ \\ :\implies\sf\ a= \dfrac{\cancel{490}\times 100}{\cancel{7}}\\ \\ \\ :\implies\sf\ a= 70\times 100\\ \\ \\ :\implies\underline{\boxed{\sf{\red{\ a= 7000}}}}$

Answer 2

${\large{\pmb{\sf{\underline{Question \: 1)}}}}}$

Question : Find the area of rectangle, whose perimeter is 240 metres and length is 40 metres.

Given that :

• Perimeter of rectangle = 240 m
• Length of rectangle = 40 m

To find :

• Area of the rectangle

Solution :

• Area of the rectangle =

Using concept :

• Formula to find perimeter of rectangle.
• Formula to find area of rectangle.

Using formula :

• P of rectangle = 2(l+b)
• A of rectangle = l×b

Where,

• P denotes perimeter
• A denotes area
• l denotes length
• b denotes breadth

Full solution :

~ As we know that the formula to find perimeter of rectangle is 2(l+b). Now we have to put the values according to this formula and let's find breadth of this rectangle.

➟ P = 2(l+b)

➟ 240 = 2(40+b)

➟ 240 = 80 + 2b

➟ 240-80 = 2b

➟ 160 = 2b

➟ 160/2 = b

➟ 80 = b

➟ b = 80 m

➟ Breadth = 80 metres

• Henceforth, the breadth of the rectangle is 80 metres.

~ Now let's find the area of the rectangle. We have to use formula to find area of rectangle and have to put values according to that formula i.e., l×b

➟ A = l×b

➟ A = 40 × 80

➟ A = 3200 m²

➟ Area = 3200 metres²

• Henceforth, 3200 metres² is the area of the rectangle.

${\large{\pmb{\sf{\underline{Question \: 2)}}}}}$

Question : Find the whole quantity if 7% of it is 490

Given that :

• 7% of whole quantity is 490

To find :

• Whole quantity

Solution :

• Whole quantity = 7000

Assumption :

• Let whole quantity is x

Full solution :

➟ 7% of x = 490

➟ 7% × x = 490

➟ 7/100 × x = 490

➟ x = (490×100)/7

➟ x = 49000/7

➟ x = 7000

➟ Whole quantity = 7000

• Henceforth, 7000 is the whole quantity if 7% of it is 490