Area Problems The circumferences of two concentric are 176 m and 132 m respectively. what is the difference between their radii? 5 meter 7 meter 44 meter 8 meter 5 meter 7 meter 44 meter 8 meter ANSWER EXPLANATION DOWNLOAD EXAMIANS APP ? 2?R - 2?r = (176-132)? 2?(R-r) = 44? R-r = ( 44 x 7 )/ (2 x 22)= 7 m
Area Problems A rectangle has 15 cm as its length and 150 cm 2 as its area .Its area is increased to 1 1 / 3 times the original area by increasing only its length . Its new perimeter is? 50 cm 60 cm 70 cm 80 cm 50 cm 60 cm 70 cm 80 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Breadth of the rectangle = (150/15) cm= 10 cmNew area = (4/3 x 150) cm2= 200 cm2New length = 200/10 cm=20 cmNew perimeters = 2(20 + 10) cm= 60 cm
Area Problems If the radius of a circle is decreased by 50% , find the percentage decrease in its area. 75% 35% 65% 25% 75% 35% 65% 25% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP let original radius = r and new radius = (50/100) r = r/2 original area = ?r 2 and new area = ? r / 2 2 decrease in area = 3 ?r 2 / 4 * 1 ?r 2 *100 = 75%
Area Problems If the sides of a squares is increased by 25%, then the area of the squares will be increased by 125% 53.75% 50% 56.25% 125% 53.75% 50% 56.25% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required increment = 2a + [a2 / 100] %= 2 x 25 + [(252)/100)] %= 50 + (625/100)% = 56.25%
Area Problems The ratios of areas of two squares, one having its diagonal double than the other is 4:1 2:3 3:1 2:1 4:1 2:3 3:1 2:1 ANSWER DOWNLOAD EXAMIANS APP
Area Problems What is the least number of squares tiles required to pave the floor of a room 15 m 17 cm long and 9 m 2 cm broad? 844 840 814 820 844 840 814 820 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm. Area of each tile = (41 x 41) cm2. ∴ Required number of tiles = ❨ 1517 x 902 ❩ = 814
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