Question

How many tiles whose length and breadth are 12 cm and 5 cm respectively will be
needed to cover a rectangular region whose length and breadth are
area of a rectangular plot is 340 sq. m. If its breadth is 17 m, find its length
(i) 144 cm and 1 m.
(ii) 70 cm and 36 cm​

Answer 1

${\underline{\boxed{\frak{\pmb{\quad Correct\: question \::-\quad}}}}}$

• How many tiles whose length and breadth are 12 cm and 5 cm respectively will be needed to cover a rectangular region whose length and breadth are

(i) 144 cm and 1 m.

(ii) 70 cm and 36 cm

• Area of a rectangular plot is 340 sq. m. If its breadth is 17 m, find its length

⠀⠀⠀

${\underline{\boxed{\frak{\pmb{\quad Find\:out \::-\quad}}}}}$

• Numbers of tiles
• Length of rectangular plot

⠀⠀⠀

${\underline{\boxed{\frak{\pmb{\quad solution \::-\quad}}}}}$

⠀⠀⠀

⠀⠀⠀⠀ ⠀In the first question ⠀⠀

◐ Dimensions of a tile ◐

$\bullet\:\sf Length\:of \: tile = 12 cm$

$\bullet\:\sf Breadth\:of \: tile = 5 cm$

⠀⠀⠀⠀

◐ Dimensions of rectangular regions ◐

$\bullet\:\sf l = 144cm\: and \: 70 cm$

$\bullet\:\sf b = 1cm \: and \: 36 cm$

⠀⠀⠀⠀

↬ Area of one tile

⠀⠀⠀⠀⠀⠀

↬ length × breadth

⠀⠀⠀⠀

↬ 12 × 5

⠀⠀⠀⠀

↬ 60cm² ⠀

⠀⠀⠀⠀⠀⠀

∴ Area of one tile = 60cm²

⠀⠀⠀⠀

↬ Area of a rectangular region

⠀⠀⠀⠀⠀⠀⠀

↬ length × breadth

⠀⠀⠀⠀

↬ 144 × 1

⠀⠀⠀⠀

↬ 144 cm²

⠀⠀⠀

∴ Area of a rectangular region = 144 cm²

$\:$____________________________________________

⠀⠀⠀⠀

⠀⠀⠀⠀⠀⠀Number of tiles

• Number of tiles needed to cover a rectangular region whose length is 144cm and breadth is 1cm

↬$\pmb{\sf{\dfrac{Area\:of\:a\: region}{Area\:of\:one\:tile}}}$

⠀⠀⠀⠀

↬ $\sf \cancel\dfrac{144}{60}$

⠀⠀⠀⠀

↬ 2.4 tiles

⠀⠀⠀

∴ Number of tiles = 2.4

$\:$____________________________________________

• Number of tiles needed to cover a rectangular region whose length is 70cm and breadth is 36cm

↬$\pmb{\sf{\dfrac{Area\:of\:a\: region}{Area\:of\:one\:tile}}}$

⠀⠀⠀⠀

↬ $\sf \dfrac{70\times 36}{60}$

⠀⠀⠀⠀

↬ 42 tiles

⠀⠀⠀

∴ Number of tiles = 42

$\:$____________________________________________

⠀⠀⠀⠀⠀⠀In the second question

⠀⠀⠀

$\bullet\:\sf Area\:of\:a\: rectangular\:plot=340m^2$

$\bullet\:\sf Breadth\:of \: a\:plot = 17m$

⠀⠀⠀

↬ Area of a rectangle = Area of a plot⠀⠀⠀

⠀⠀⠀

↬ length × breadth = 340 m²

⠀⠀⠀

↬ l × 17 = 340

⠀⠀⠀

↬ l = 20 m

⠀⠀⠀

∴ Length of a plot = 20m

$\:$____________________________________________

Answer 2

Answer:

Area of region = 100 cm x 144 cm = 14400 cm.sq

Area of one tile = 5 cm x 12 cm = 60 cm.sq

Number of tiles =Area of region/area of one tile

​  

 = 240

Thus, 240 tiles are required.

(b) Area of region = 70 cm x 36 cm = 2520 cm.sq

Area of one tile = 5 cm x 12 cm = 60 cm.sq

Number of tiles =  Area of region/Area of one tile

​  

 = 42

Thus, 42 tiles are required.