Area Problems The length of minute hand of a wall clock is 7 cms. The area swept by minute hand in 30 minutes is? 147 sq. cm 77 sq. cm 154 sq. cm 210 sq. cm 147 sq. cm 77 sq. cm 154 sq. cm 210 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 A rectangular carpet has an area of 120 sq. m and a perimeter of 46 m . The length of its diagonal is? 20 m 17 m 15 m 16 m 20 m 17 m 15 m 16 m ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let length = a metres and breadth = b metres Then, 2(a+b)= 46 ? (a+b) =23 and ab =120 ? Diagonal = ?a2 + b2?(23)2-2 x 120?289 = 17 m
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% 56.25% 50% 125% 53.75% 56.25% 50% ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Required increment = 2a + [a2 / 100] %= 2 x 25 + [(252)/100)] %= 50 + (625/100)% = 56.25%
Area Problems The area of a trapezium is 384 sq.cm 2. If its parallel sides are in ratio 3 : 5 and the perpendicular distance between them be 12 cm, The smaller of parallel sides is? 20 cm 24 cm 36 cm 30 cm 20 cm 24 cm 36 cm 30 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the sides of trapezium be 5k and 3k, respectively According to the question, (1/2) x [(5k + 3k) x 12] = 384? 8k = (384 x 2)/12 = 64 ? k = 64/8 = 8 cmLength of smaller of the parallel sides = 8 x 3 = 24 cm
Area Problems The diagonal of a rectangle is √41 cm and its area is 20 sq. cm. The perimeter of the rectangle must be: 9 cm 41 cm 18 cm 20 cm 9 cm 41 cm 18 cm 20 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP √l2 + b2 = √41. Also, lb = 20. (l + b)2 = (l2 + b2) + 2lb = 41 + 40 = 81 ⟹ (l + b) = 9. ∴ Perimeter = 2(l + b) = 18 cm
Area Problems The ratio of the corresponding sides of two similar triangles is 3 : 4, The ratio of their areas is? 3 : 4 9 : 16 4 : 3 ? 3: 2 3 : 4 9 : 16 4 : 3 ? 3: 2 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of similar triangle = Ratio of the square of corresponding sides = (3x)2 / (4x)2 = 9x2 / 16x2 = 9/16 = 9 : 16
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