Question

The cost of carpeting a room is ₹120. If the width had been 4 meters less, the cost of the carpet would have been ₹20 less. The width of the room is
a. 24m
b. 20m
c. 25m
d. 18.5m​

Answer 1

Answer:

a. 24m

Step-by-step explanation:

let the rate of painting =Rs. x/metre2

∴ Length×breadth×x=Rs.120........(i)

Length×(breadth−4)×x=Rs.100.........(ii)

from equation (i) and (ii)

breadth / breadth−4 =120 / 100=  65

breadth = 24m

Answer 2

The width of the room is 24m.

Explanation :

Assuming the let rate of painting as :

$\sf \implies \dfrac{Rs.y}{Metre^2}$

So,

$\sf \implies \: Length \times \: Breadth \times \: y=Rs.120 \quad \: [ \bf \: Equation : 1 \: ]$

$\sf \implies Length \times (Breadth-4)\times y=Rs.100\quad[\bf \; Equation : 2\;]$

From Equation 1 & 2,

$\implies \sf \dfrac {Breadth}{Breadth−4} =\dfrac{120}{100}= \dfrac{6}{5}$

Hence,

The width of the room is 24m.