Question

The length and the breath of a rectangle is 80 m and 40 m. if the length increases by 5 percent and decrease by 5 percent . what will be the difference in perimeter

Answer 1

Given :-

The length and the breath of a rectangle are 80 m and 40 m. if the length increases by 5 percent and decreases by 5 percent.

To Find :-

What will be the difference in perimeter

Solution :-

${\large{\boxed{\bf{\dag Original\;Perimeter:-}}}}$

↣ Perimeter = 2(l + b)

↣ Perimeter = 2(80 + 40)

↣ Perimeter = 2(120)

↣ Perimeter = 240 m

${\large{\boxed{\bf{\dag New\;Perimeter:-}}}}$

↣ New Length = 80 + 5% of 80

↣ New Length = 80 + 5/100 × 80

↣ New Length = 80 + 5/5 × 4

↣ New Length = 80 + 4

↣ New Length = 84 m

↣ New Breadth = 40 - 5% of 40

↣ New Breadth = 40 - 5/100 × 40

↣ New Breadth = 40 - 5/5 × 2

↣ New Breadth = 40 - 2

↣ New Breadth = 38 m

↣ New Perimeter = 2(l + b)

↣ New Perimeter = 2(84 + 38)

↣ New Perimeter = 2(122)

↣ New Perimeter = 244 m

↣ Difference = 244 - 240

↣ Difference = 4 m