Question

The shaded part in the given figure is covered with cement. If its costs Rs. $84$ to cement an area of $3$ $c{m}^2$, find the total cost of cementing.

• A. Rs. $8820$
• B. Rs. $8125$
• C. Rs. $8610$
• D. Rs. $8804$

Answer 1

The correct option is A Rs. $8820$

Area of larger rectangle $=(32\times 25)c{m}^2=800c{m}^2$
Also, area of smaller rectangle$=485c{m}^2$
$\therefore$ Area of shaded part $=(800-485)c{m}^2=315c{m}^2$
Now,
Cost of cementing of $3c{m}^2=$Rs. $84$
$\therefore$ Cost of cementing of $1c{m}^2=(84÷3)=$Rs. $28$
$\therefore$ Cost of cementing of $315c{m}^2$
$=$Rs. $(28\times 315)=$Rs. $8820$.