Question

the length, breath and height of a room are 5 m ,4m and 3m respectively.find the cost of white washing the walls of the room and the ceiling at the rate of RS 7.50per m²​

Answer 1

Answer:

RS. 555

Step-by-step explanation:

NOTE :

• Total Surface Area of Cuboid= 2(lb + bh +lh)
• Area of the rectangle = l*b

SOLUTION

Total area painted will be = Area of cuboid - area of rectangle

( Note : it is considered as the land is not painted and hence it is subtracted )

Area of cuboid = 2(lb + bh +lh)

= 2 ( 5*4 + 4*3 + 3*5 )

= 2 ( 20 + 12 + 15 )

= 2 ( 47 )

= 94 m^2

Area of the rectangle = l*b

= 5*4

= 20

Total area painted = 94 - 20 = 74

TOTAL COST = Area painted * cost

Total cost = 74 * 7.50 = RS. 555

Answer 2

Answer:

The weighing machine measures this apparent weight and hence the mass indicated by it is less than the actual mass. Our actual mass will be more than 42 kg.