Question

The ratio of the length and breadth of a rectangle is 4:7. If the length is 28 m. What will be the breadth? Two numbers are in the ratio of 2:5. If the first number is 30, find the second.​

Answer 1

Answer:

Formulae Used:

Perimeter of a rectangle = 2 × (length + breadth)

Area of a rectangle = length × breadth

Solution:

Let the length of the field be 7x and breadth be 4x.

So, perimeter of the field = 2 × (7x + 4x) = 22x

Also, area of the field = 7x × 4x = 28x2

Ratio of perimeter to the area is 11 : 28

⇒ 22x/28x2 = 11 : 28

⇒ x = 2

Hence, length of the field = 7× 2 = 14 m

∴ The length of the field is 14 m

Answer 2

The ratio of the length and breadth of a rectangle is 4:7. If the length is 28 m. What will be the breadth?

Let the ratio constant be x.

Therefore, the length and breadth will be 4x and 7x respectively.

Length = 28m

4x= 28m

x = 28/4

x = 7 m

Breadth = 7x = 7*7 = 49m

________________

Two numbers are in the ratio of 2:5. If the first number is 30, find the second.

Let the ratio constant be x

Therefore, the numbers will be 2x and 5x.

2x = 30

x = 15

Second Number = 5x = 5*15 = 75