If the length and breadth of a rectangular ro | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) Let the length and breadth of the rectangular room be $l$ and $b$ respectively.According to the first condition:$(l+1)(b+1) - lb = 21$$lb + l + b

Vedclass · Accepted Answer

$40$

Vedclass · Answer

(D) Let the length and breadth of the rectangular room be $l$ and $b$ respectively.According to the first condition:$(l+1)(b+1) - lb = 21$$lb + l + b + 1 - lb = 21$$l + b + 1 = 21$$l + b = 20$ $...(1)$According to the second condition:$(l+1)(b-1) - lb = -5$$lb - l + b - 1 - lb = -5$$-l + b - 1 = -5$$-l + b = -4$$l - b = 4$ $...(2)$Adding equations $(1)$ and $(2)$:$(l + b) + (l - b) = 20 + 4$$2l = 24$$l = 12\, m$Substituting $l = 12$ in equation $(1)$:$12 + b = 20$$b = 8\, m$The perimeter of the floor is given by the formula $P = 2(l + b)$.$P = 2(12 + 8) = 2(20) = 40\, m$.

If the length and breadth of a rectangular room are each increased by $1\, m$,then the area of the floor is increased by $21\, m^2$. If the length is increased by $1\, m$ and the breadth is decreased by $1\, m$,then the area is decreased by $5\, m^2$. The perimeter of the floor is.......$m$.

Similar Questions

$A$ room $5\, m \times 8\, m$ is to be carpeted leaving a margin of $10\, cm$ from each wall. If the cost of the carpet is ₹ $18$ per $m^2$,then the cost of carpeting the room will be (in $Rs.$)

If a diagonal of a square is doubled,how does the area of the square change?

Find the area of a triangle in which base is $1.5\, m$ and height is $75\, cm$? (in $sq. cm.$)

The perimeter of an isosceles triangle is $306\, m$ and each of the equal sides is $\frac{5}{8}$ of the base. Find the area.

In a triangle $ABC$,$AB + BC = 12 \text{ cm}$,$BC + CA = 14 \text{ cm}$,and $CA + AB = 18 \text{ cm}$. Find the radius of the circle (in $\text{cm}$) which has the same perimeter as the triangle.

Vedclass Test Series

Exam Paper Generator

Online Exam Module