The length and breadth of a rectangular hall are $40m$ and $18m$ respectively. Find the number of tiles $1m.50cm$ that will cover the floor of the hall.

Hint: In this type of question first we have to check the given values carefully then change all the measure units the same as in this question we have cm and m both, we have to change meter into centimeter.


Complete step-by-step answer:
In this question length and breadth of the hall is given which is $40m$ and $18m$
First, we have to convert meter into centimeter
Length of hall is $40m$
Here we multiply 40 to 100 to convert meter into centimeter
$40m = 40.100 = 4000$cm
Breadth of hall is $18m$
Here we multiply 18 by100 to convert meter into centimeter
$ = 18.100$
$ = 1800cm$
Area of rectangular hall
=$L.B = 4000.1800$
=$7200000c{m^2} $
Here we get our area of hall.
Now, we will find out what is area of single tile
Length of tile = $1m$
=$1m.100$
Change meter into centimeter
multiply 1 by 100
=$100cm$
Breadth of tile $ = 50cm$
Tiles is rectangular in shape so the area of one tile is length into breadth
\[ = 50cm.100cm\]
Area of one tile$ = 5000c{m^2} $
Number of required tiles
= Area of the hall / Area of the tile
=$7200000/5000$
=$7200/5$
=1440

The number of tiles required is 1440.

Note: Alternative method
Length of a rectangular hall $L = 40m$
Breadth of the rectangular hall $B = 18m$
We, can find out area of hall which is =Length into breadth
$ = 40.18$=$720{m^2} $
Length of 1 tile=$1m$
Breadth of 1 tile=$50cm$
=$0.5m$ Here we change cm into m ($50/100$)
The area of each tile
=Length. Breadth
=$1.0.5 = 0.5{m^2} $ Multiply 1 by 0.5
Therefore, the numbers of tiles required
Area of hall. Area of tile
=$720/0.5$
$ = 1440$