Question

find the cost of flooring a room 6.5 m by 5 m with square tiles of side 25 cm at the rate of 1880 per hundred tiles

Answer 1

length of floor of room = 6.5 m = 650 cm
breadth of floor of room = 5 m = 500 cm
area of floor of room = length × breadth
$500 \times 650 = 32500 {cm}^{2}$
Now, 
length of each side of square tile = 25 cm

area of 1 square tile = side × side 
 
$= 25 \times 25 = 625 {cm}^{2}$
$no. \: of \: tiles \: required = area \: of \: floor \div area \: of \: each \: square \: tile$
$32500 \div 625 = 520$
Cost of 100 tiles = Rs 1880
cost of 1 tile = 
$rs(1880 \div 100)$
= Rs 18.80
Cost of 520 tiles = Rs (18.80 × 520) = Rs 9776

Answer 2

length of floor of room = 6.5 m = 650 cm
breadth of floor of room = 5 m = 500 cm
area of floor of room = length × breadth
500 \times 650 = 32500 cm^2
length of each side of square tile = 25 cm

area of 1 square tile = side × side = 25* 25 = 625 cm^2
No. of tiles required = area of floor / area of each square tile
32500 / 625 = 520
Cost of 100 tiles = Rs 1880
cost of 1 tile = 1880 / 100= Rs 18.80
Cost of 520 tiles = Rs (18.80 × 520) = Rs 9776