Area Problems If the sides of a squares is increased by 25%, then the area of the squares will be increased by 50% 53.75% 125% 56.25% 50% 53.75% 125% 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 ratio of the area of the circumcircle and the incircle of a square is ?2 : 1 1 : ?2 2 : 1 1 : 2 ?2 : 1 1 : ?2 2 : 1 1 : 2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of the areas of the circumcircle and incircle of a square = [(Diagonal)2?] / [(Side)2?]= [(Side x ?2)2] / (Side)2 = 2/1 or 2 : 1
Area Problems The length of minute hand of a wall clock is 7 cms. The area swept by minute hand in 30 minutes is? 210 sq. cm 154 sq. cm 77 sq. cm 147 sq. cm 210 sq. cm 154 sq. cm 77 sq. cm 147 sq. cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Angle swept in 30 min= 180° Area swept = [(22/7) x 7 x 7] x [180°/360°] cm2 = 77 cm2
Area Problems The sides of a triangular board are 13 meters, 14 meters and 15 meters. The cost of paining it at the rate of Rs. 8.75 per m 2 is? Rs. 730.80 Rs. 688.80 Rs. 722.50 Rs. 735 Rs. 730.80 Rs. 688.80 Rs. 722.50 Rs. 735 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP s = (13 + 14 + 15 ) / 2 = 21, s-a = 8 , s-b = 7, s-c= 6? Area to be painted = ? [s(s-a) (s-b) (s-c)]=? [21 x 8 x 7 x 6] m2= 84 m2? Cost of painting = Rs. (84 x 8.75) = Rs. 735
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? 80 cm 50 cm 70 cm 60 cm 80 cm 50 cm 70 cm 60 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 In a circle of radius 21 cm an arc subtends an angle of 72° at the centre. The length of the arc is? 21.6 cm 19.8 cm 13.2 cm 26.4 cm 21.6 cm 19.8 cm 13.2 cm 26.4 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Arc length = 2?r (?° / 360°) = 2 x (22/7) x 21 x (72° / 360°) cm= 26.4 cm
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