Question

Daniel is painting the walls and ceiling of a cuboidal hall with length, breadth and height of 15m, 10m and 7m respectively. From each can of paint 100 ${m^2}$ of area is painted. How many cans of paint will she need to paint the hall?

Answer 1

Hint: Here, we need to find the total area of the walls and ceiling and then by dividing it with 100 ${m^2}$ we can obtain the number of cans required to paint the hall.

Complete step-by-step answer:
Given length, breadth and height is
$l = 15$ m $\to$ ‘l’ represents length of the cuboidal hall
$b = 10$ m $\to$ ‘b’ represents breadth of the cuboidal hall
$h = 7$ m $\to$ ‘h’ represents height of the cuboidal hall
Now, calculate the total area to be painted
$
   \Rightarrow 2(l + b) \times h + l \times b \\
   \Rightarrow 2(15 + 10) \times 7 + 15 \times 10 \\
   \Rightarrow 350 + 150 \\
   \Rightarrow 500{m^2} \\
$
By one paint can, we can paint only 100 ${m^2}$ area
Now, number of paint cans required to paint 500 ${m^2}$ area
$ \Rightarrow \dfrac{{500}}{{100}} = 5$ cans
$\therefore $ 5 cans are required to paint 500 ${m^2}$ area.

Note: In these types of problems we have to calculate the areas of the given regions based on what is asked and then use the necessary restrictions mentioned in the problem statement to determine either the cost or the quantity of some item required.