Let circumference = 100 cm . Then, ? 2?r = 100? r = 100/2? =50/?? New circumference = 105 cm Then, 2?R = 105? R = 105 / (2?)&rArr Original area = [ ? x (50/?) x (50/?) ] = 2500/? cm2? New Area = [? x (105/2?) x (105/2?)]= 11025 / (4?) cm2? Increase in area = [11025/(4?)] - 2500/? cm2= 1025 / 4? cm2Required increase percent [1025/(4?)] x 2500/? x 100 = 41/4%= 10.25%
Area of square room = (10)2 = 100 sq m= 100 x (100)2 sq cm= 100 x 100 x 100 sq cmNow, area of tiles = (50)2 = 50 x 50 sq cm? Number of tiles needed = (Area of square room) / (Area of tile)= (100 x 100 x 100) / (50 x 50) = 400Hence, 400 tiles will be needed.