Area Problems The area of rectangle whose length is 5 more than twice its width is 75 sq units. What is the perimeter of the rectangle? 24 unit 30 unit 40 unit 20 unit 24 unit 30 unit 40 unit 20 unit ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let the width of the rectangle = k units? Length = (2k + 5) units.According to the question,Area = k(2k + 5)? 75 = 2k2 + 5k? 2k2 + 5k - 75 = 0 ? 2k2 + 15k - 10k - 75 = 0 ? k(2k + 15) - 5(2k + 15) = 0 ? (2k + 15) (k - 5) = 0 ? k = 5 and -15/2Width cannot be negative. ? Width = 5 units? Length = 2x + 5 = 2 x 5 + 5 = 15 unit? perimeter of the rectangle = 2(15 + 5) = 40 units
Area Problems A hall 20 m long and 15 m broad is surrounded by a verandah of uniform width of 2.5 m. the cost of flooring the verandah at the rate of 3.50 per sq. meter is? Rs. 500 Rs. 700 Rs. 600 Rs. 800 Rs. 500 Rs. 700 Rs. 600 Rs. 800 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of verandah = [(25 x 20) -(20 x 15)] m2= 200 m2? Cost of flooring = Rs. (200 x 3.50)= Rs. 700
Area Problems In ? ABC ,sides BC = 10 cm and height AD = 4.4 cm. If AC = 11 cm. Then altitude BE equals? 5 cm 5.5 cm 4 cm 5.6 cm 5 cm 5.5 cm 4 cm 5.6 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP We know that area of triangle = ( base x height ) / 2So area of triangle = (BC x AD) / 2 = (AC x BE) / 2 ? (10 x 4.4) / 2 = (11 x h) / 2? h= (10 x 4.4)/11 = 4 cm
Area Problems A tank is 25m long 12m wide and 6m deep. The cost of plastering its walls and bottom at 75 paise per sq m is Rs. 258 Rs. 458 Rs. 358 Rs. 558 Rs. 258 Rs. 458 Rs. 358 Rs. 558 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area to be plastered = 2 l + b × h + l × b = 2 25 + 12 × 6 + 25 × 12 = 744 s q . m Cost of plastering = 744 × 75 100 = R s . 558
Area Problems The ratio of the area of square of side a and equilateral triangle of side a is? 2 :1 4 :3 2 : ?3 4 : ?3 2 :1 4 :3 2 : ?3 4 : ?3 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ratio of area = a2/ ?(3/4) a2= 4/?3 = 4:?3
Area Problems The length of a rectangle is twice its breadth. If its length is decreased by 5 cm and the breadth is increased by 5 cm, the area of the rectangle is increased by 75 cm 2 . Therefore , the length of the rectangle is? 30 cm 40 cm 20 cm 50 cm 30 cm 40 cm 20 cm 50 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let breadth = b, length = 2b? Area of rectangle = 2b x b = 2b2As per question. ? (2b - 5 ) (b + 5 ) = 2b2 + 75? 5b = 75 + 25? 5b = 100? b = 100 / 5 = 20Hence, length of the rectangle =2b = 2 x 20 = 40 cm.
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