Area Problems The area of the sector of a circle, whose radius is 12 meters and whose angle at the centre is 42, is? 39.6 sq. meters 52.8 sq. meters 79.2 sq. meters 26.4 sq. meters 39.6 sq. meters 52.8 sq. meters 79.2 sq. meters 26.4 sq. meters ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Area of the sector = [(22/7) x 12 x 12] x [42°/360°] m2 = 52.8 m2
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? 50 cm 20 cm 40 cm 30 cm 50 cm 20 cm 40 cm 30 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.
Area Problems A triangle with three equal sides has its area equal to 3?3 sq cm . Find its perimeter . 6?3 cm 7?3 cm 5?3 cm 2?3 cm 6?3 cm 7?3 cm 5?3 cm 2?3 cm ANSWER EXPLANATION DOWNLOAD EXAMIANS APP According to the question,?3a2/4 = 3?3 [ side = a, and area = ?3a2/4] ? a2/4 = 3 ? a2 = 3 x 4 ? a = 2?3? Required perimeter = 3a =3 x 2?3 = 6?3 cm
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? 840 814 820 844 840 814 820 844 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
Area Problems The length of a rectangular plot is 20 metres more than its breadth. If the cost of fencing the plot @ 26.50 per metre is Rs. 5300, what is the length of the plot in metres? None of these 120 40 Data inadequate None of these 120 40 Data inadequate ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Let breadth = x metres. Then, length = (x + 20) metres. Perimeter = ❨ 5300 ❩ m = 200 m. 26.50 ∴ 2[(x + 20) + x] = 200 ⟹ 2x + 20 = 100 ⟹ 2x = 80 ⟹ x = 40. Hence, length = x + 20 = 60 m
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. 458 Rs. 258 Rs. 558 Rs. 358 Rs. 458 Rs. 258 Rs. 558 Rs. 358 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
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